To watch Tony Brown's interview with President Reagan is to hear descriptions of a land that bears some superficial resemblance to the United States, but is a nation scarcely troubled by economic woes and unfearful of unemployment, and where the poor have survived federal budget reductions undamaged.

Poor people are not going to be pushed off the food stamp rolls, Reagan says at one point in the 30-minute interview broadcast tonight at 9 on Channels 26 and 32. As he sees it, the only people to be deprived of food stamps are the undeserving rich. The only food stamp recipients who have to worry, Reagan indicates, are those like two college students he heard of when he was governor of California. One was getting stamps although his father earned more than $100,000 a year. The other's studies to become a witch were being supported by food-stamp aid, Reagan said.

Reagan is not asked and does not explain how there can be so many such cases. According to administration forecasts, the total number of stamp recipients will decline from roughly 21 million now to 17.7 million in fiscal 1983 as a result of Reagan's budget cuts.

Brown, the host of "Tony Brown's Journal," which is described as a "series about black people for all people," lets the president's statements stand. Brown's questions cover the agenda of black concerns about Reagan, but he asks no follow-up questions. The result is a bland exchange studded with such Reagan observations as that he can hardly be against children because, "I'm a grandparent."

Reagan acknowledges that his federalism program, designed to turn greater responsibilities over to state and local governments, might alarm blacks who remember less-than-fair treatment at the hands of their local governments, but he declares, without explanation, that he won't let it happen again. "The duty and obligation of the federal government is to guarantee the constitutional rights of every citizen in this country," Reagan says, even "at the point of bayonet, if necessary."

After all, he says with a smile and a gentle apology for getting partisan, when local governments were violating blacks' rights the federal government shut its eyes for a long time and the people running the federal government back then were, you guessed it, Democrats. Does the president really believe he can make a partisan issue out of past abuses against blacks?

Brown quietly asks the president why some people believe he is a racist and, the president, equally quietly and good-naturedly, replies, "If I have an intolerance at all, it is an intolerance for bigotry and prejudice."

Reagan says it would have been better had he introduced his legislation to bar tax exemptions for private schools that discriminate before he canceled the Internal Revenue Service regulation that had the same effect, but despite many indications that his legislation is in trouble in the Senate, Reagan predicts its passage.

Black Americans never have succumbed to Reagan's charm. An ABC News exit poll found that 13 percent of blacks voted for Reagan. The most recent Washington Post-ABC News poll, taken after his first year in office, found only 8 percent of blacks approve of the way he is handling the presidency while 87 percent disapprove.

Brown asks Reagan what the president might do differently with regard to black Americans. The president indicates he does not see a need to make significant changes.