The Reagan administration, moving toward increased military involvement in Central America, yesterday unveiled a foreign-aid budget that would increase military assistance to Guatemala from $300,000 to $35.3 million.

Congress has been reluctant in the past to give Guatemala substantial aid because of its human-rights record.

That part of the $14.77 billion overall request for fiscal 1986 is relatively small in comparison with packages being proposed for such traditional U.S. allies as Israel, Egypt, Pakistan and the Philippines.

But, in comparative terms, the jump is so large that it seems certain to trigger new charges from congressional critics that the administration is seeking to resolve Central America's conflicts by emphasizing military solutions.

The administration also requested $483.4 million in economic and military aid packages to help El Salvador combat leftist guerrilla opponents and $231 million for Honduras, where the administration has been trying to strengthen the armed forces to help counter the leftist Sandinista government in neighboring Nicaragua.

Guatemala received U.S. economic aid for the last two years but, except for $300,000 this year for training, has had no U.S. military assistance since 1977 because of its poor human-rights record.

However, administration officials said they believe that the request for an additional $35 million in support funds and credits to buy U.S. weapons is justified because the Guatemalan military regime has promised elections that could produce a civilian government by Oct. 1.

Sen. Christopher J. Dodd (D-Conn.), a persistent critic of President Reagan's Central America policy, said the Guatemala request is a surprise to Congress and added: "Good luck to them if they think they can get it.

"It's exorbitant, excessive and not justified by anything that has happened there."

The amount proposed for El Salvador is only slightly more than its $473.6 million this year. But officials said that decisions have not been made about additional requests for El Salvador and that Congress could be asked later to increase the amount if the Salvadoran government has difficulty combating guerrillas.

The overall aid request is weighted heavily in favor of military assistance.

Of the total, $9.4 billion or 62.1 percent is for security programs, and $5.3 billion or 37.9 percent is for economic aid directly or indirectly to individual countries.

As is customary, almost half would go to Israel and Egypt. The request seeks $2.3 billion in economic and military aid for Egypt and $1.8 billion in military aid for Israel, with the understanding that an additional economic aid request for Israel, expected to be at least $1.2 billion, will be submitted later.

Administration officials contended that it preserves the ratio between mililtary and economic aid followed since Reagan became president. They said only 43.7 percent of the proposed total is for security assistance and the rest for economic aid.

However, their economic aid figure includes $2.8 billion, or 18.4 percent of the total, for Emergency Support Funds. These are given to a country for economic assistance, such as combating balance-of-payments problems, but are regarded by law as security assistance because their purpose is to provide a supplement enabling recipients to avoid diverting money from defense budgets.

One significant departure was a request for sharply increased aid for Peru ($128 million), Bolivia ($52.8 million) and Ecuador ($46.4 million), where the administration fears increased leftist guerrilla activity and terrorism. The administration also said it would ask Congress to add two large supplemental appropriations to the fiscal 1985 budget: $235 million for previously announced added famine relief for drought-stricken areas of Africa and $237 million to meet past-due payments owed lending institutions.