As it allegedly attracted automobile magnate John Z. De Lorean, so has the southern California cocaine underground drawn thousands of others -- Florida grandmothers, San Francisco bankers, Colombian peasants -- into a secret market producing as much as $3 billion a year in this state alone and still growing.

The high incomes and pressures of the music, movie and other local industries have turned cocaine into such a highly available and favorite form of recreation that the 60 pounds valued at $6.5 million seized during the De Lorean arrests this week would have met the state's needs for only a day.

President Reagan has announced plans for a drug crackdown that includes cutting off cocaine shipments into South Florida, but so far such efforts seem only to be encouraging more and larger shipments of the stimulating white powder into southern California.

Some police and prosecutors here noted a significant increase in the size of shipments of cocaine being seized, now running as high as 100 to 130 pounds at a time.

Assistant U.S. Attorney Robert Perry said it suggests cocaine traffickers are abandoning their favorite route from Colombia to Florida, from which smaller shipments of the drug were sent on to California.

Vice President Bush's antidrug task force in Florida has made the southeastern United States a less attractive place to bring in large shipments. Many of them now seem to be coming directly to southern California by boat or airplane from the coast of Colombia.

Drug Enforcement Administration (DEA) spokesman Robert Feldkamp said 40 to 48 metric tons of cocaine entered the United States in 1981, about 50 percent more than the estimate for the previous year.

Feldkamp said DEA analysts expect at least 48 metric tons to enter the country this year, and analysts here have estimated that perhaps 20 percent of the national total eventually arrives in California.

DEA seizures of cocaine in the Los Angeles area increased 37 percent from fiscal year 1981 to fiscal 1982, which ended Oct. 1, DEA agent Charles Bullock said. Los Angeles Police Department narcotics analyst Don Bays said police seizures this year were running 42.8 percent ahead of 1981.

Investigators say the larger seizures are in part the result of catching the most important traffickers, but also reflect an increasing volume of cocaine coming into the area; the usual rule of thumb has been that 90 percent of illegal cocaine reaches consumers.

One cocaine sales operation in Los Angeles' San Fernando Valley was discovered after the fact to have earned $73 million in seven months, stunning investigators who often have to rely on informants within organizations to stay in touch with drug deals.

"If I don't know about a group that is making $10 million a month, how can I tell you how we're doing against dope?" said Perry, who has been prosecuting drug cases here for five years.

Southern California sucks in such huge quantities of cocaine, Bays said, because "it has some fairly wealthy communities and it is kind of an avant-garde area."

The good weather, he said, adds to the variety of social occasions at which the drug can be used. The profits and tensions of the entertainment industry create an eager clientele. "It's an upper a stimulant ," Bays said. "So people in the music industry say it helps them keep performing for hours."

One major cocaine case set for trial later this year, known to attorneys as the "Grandma Mafia" case, involved "middle-aged, middle-class ladies, some of them grandmothers, who wanted to make a lot of money," said Perry.

One of them, 46-year-old Barbara Mouzin, had been working in a Florida clothing business when she allegedly became involved in currency exchange and then drug trafficking between the United States and Colombia, Perry said. In a telephone conversation taped by investigators, he said, a colleague of hers said the clothing business was doing so poorly that he was glad they had the sideline.

Mouzin allegedly approached a banker in southern California and asked him to accept large amounts of cash without filing a currency transaction report, a classic form of money "laundering" that allows drug sellers to avoid detection by drug investigators and the Internal Revenue Service, Perry said.

He said the banker contacted authorities and in the end Mouzin was dealing with government agents posing as launderers. In just eight months, Perry said, Mouzin allegedly handled $25 million, in deposits ranging up from $70,000.

Many Californians have become involved as currency exchangers, exchanging money from drug sellers in California at a favorable discount and returning it to Colombian drug exporters in the form of legal pesos, at another discount favorable to the exchanger.

Others who have become involved in the growing flow of cocaine into this area play roles that are not quite so pleasant, such as the people Perry described as "poor, itinerant Colombian peasants" who actually swallow cocaine wrapped in teeny packages and fly here to deliver it before it passes through their digestive tracts.

Perry said they are paid $1,000 for their work, which in one case involved the swallowing of 185 cocaine packs, wrapped in the snipped-off fingers of surgical gloves. If any of the packages broke in the intestines, Perry added, the courier could die.

Cocaine, derived from the leaves of the cocoa plants grown in South America, is usually sniffed through the nose and creates a temporary feeling of euphoria. Users and much of the general public here look on cocaine as a fairly harmless pastime, so in arguing for a $20 million bail for De Lorean on cocaine trafficking conspiracy charges, Assistant U.S. Attorney James Walsh pointed out that De Lorean had also allegedly discussed importing heroin.

Multimillion-dollar bails used to be rare, Perry said, and many dealers posted bond and left the country to avoid trial. Now De Lorean, at $5 million bail, and his alleged accomplice, William Morgan Hetrick, at $20 million bail, remain jailed in a federal penitentiary, having been unable to persuade magistrates to reduce the amounts.