President Reagan called in 25 Democratic House members and did some "arm twisting" yesterday as the administration stepped up efforts to defeat the nuclear freeze resolution on which House debate resumes today.

Before Reagan met with the lawmakers, Defense Secretary Caspar W. Weinberger held a Pentagon news conference to unveil proposals for making accidental nuclear war less likely, including upgrading the "hot line" now connecting Washington and Moscow. He said there was no connection between his news conference and the freeze debate.

White House spokesman Larry Speakes freely acknowledged that Reagan did some heavy lobbying against the freeze when, in refusing to identify the House visitors, he commented: "We don't put out the arm-twisting list."

Reagan and Weinberger warned the 25 Democrats that approving the freeze resolution would send the wrong signal to the Soviet Union and the rest of the world. Rep. William J. Hughes (D-N.J.) said Weinberger called passage of the freeze resolution "tantamount to unilateral disarmament."

But the warnings apparently failed to persuade at least some of the Democrats.

"I am as undecided now as I was when I went in," said Rep. Glenn English (D-Okla.).

Lobbying by Reagan and his deputies will be accompanied by Republican attempts on the floor to weaken the freeze resolution, or at least muddy the waters, before the measure is voted upon. The vote may be put off until next week, House leaders said yesterday, to let members attend the funeral of Rep. Phillip Burton (D-Calif.), who died Sunday in San Francisco of an aneurism.

Freeze supporters expressed confidence yesterday that they could defeat amendments to weaken the resolution.

If that turns out to be the case, said Rep. Dick Cheney (R-Wyo.), who is on a damage-limiting mission for the president, "We'll muddy the waters a bit." And even if the freeze resolution survives such attacks, Cheney continued, "it will be perceived as a symbol," not a mandate. "It is not going to pass the Senate and the president won't sign it."

The freeze resolution, House Joint Resolution 13, is sponsored by Rep. Clement J. Zablocki (D-Wis.), chairman of the Foreign Affairs Committee, and 200 other representatives.

It would instruct U.S. officials negotiating arms reductions to consider it their primary objective to discuss with the Soviets when and how to achieve "a mutual and verifiable" freeze on the testing, production and further deployment of nuclear warheads, missiles and other delivery systems.

The first freeze amendment on today's schedule is sponsored by Elliott H. Levitas (D-Ga.) and would require two old nuclear weapons to be retired for every new one deployed. Leaders of the nuclear freeze campaign oppose the amendment on the grounds that it would allow both sides to keep deploying first strike nuclear weapons.

"All it does is reduce the inventory of old bombs," complained Reuben McCornack, a spokesman of the freeze movement. He portrayed freeze advocates as "very confident, very positive," partly because they are better organized than the last time the issue was joined.

Weinberger has emphasized that the administration and the freeze advocates have the same objective, eliminating nuclear weapons from the earth, but he also contends that continued modernization of U.S. offensive forces is vital to that goal.

The defense secretary yesterday did not present the administration's proposals for minimizing the chance of nuclear miscalculation in the freeze context, but he said they might ease tensions between the United States and Soviet Union.

Weinberger said he presented the proposals to Soviet Ambassador Anatoliy F. Dobrynin at the State Department last Thursday. Dobrynin was noncommittal as he politely received the proposals, Weinberger said.

Besides upgrading the principal hot line, the administration's "confidence building" measures include: a separate hot line between the Pentagon's command center and its counterpart in the Soviet Union to "allow rapid exchange of highly technical information that could be essential to understanding and therefore resolving a nuclear or other military crisis;" data links between the Soviet foreign ministry in Moscow and its embassy in Washington and between the State Department in Washington and the U.S. Embassy in Moscow, and an international mechanism that would swing into action if terrorist groups sought nuclear weapons or exploded one.

Reagan has not signed off on those proposals, the Pentagon said.