Democratic and Republican members of the Senate Finance Committee, in a replay of their fight last month over a Canadian free-trade agreement, yesterday accused the Reagan administration of branding any congressional trade proposal it disagrees with as protectionist.

"The administration is guilty of rhetorical overkill, which it would be well advised to abandon and start getting serious about the issue," complained Sen. John C. Heinz (R-Pa.).

Sen. Russell Long (D-La.) joined in the criticism, suggesting that "you fellows should take a nice vacation" and give Congress 30 days "to straighten this thing America's record trade deficit out."

U.S. Trade Representative Clayton Yeutter appeared flustered by the bipartisan beating he took from the senators, who spent most of a two-hour trade subcommittee hearing criticizing administration trade policies.

At one point, the usually unflappable Yeutter addressed the chairman, Sen. John C. Danforth (R-Mo.), as Heinz. Later, he referred to Treasury Secretary James A. Baker III, who received a milder reception from the same group Tuesday, as "Sen. Baker."

The hearing provided a clear signal that trade frustrations cross party lines in Congress, despite administration attempts to paint a House Democratic trade package in partisan political terms.

It also highlighted the growing impatience of senators from both parties with what many consider the Reagan administration's take-it-or-leave-it attitude on trade legislation. The frustration almost cost President Reagan permission to negotiate a free-trade agreement with Canada, which squeaked through the Finance Committee last month only after presidential arm-twisting.

Sen. Max Baucus (D-Mont.) reminded Yeutter of Reagan's close call on the Canadian trade initiative and said, "This administration is unwilling to meet us halfway. This administration wants to take all the marbles home."

He said President Reagan and other administration officials "block progress" when they use "pejoratives" to describe the House Democratic trade package.

Long added that it was overkill for the White House to call Danforth a protectionist even though he had played a major role in opposing measures to protect the auto and textile industries.

Yeutter insisted the administration is willing to work with Congress on trade, but acknowledged its objectives are far narrower than those of the lawmakers.

He listed four administration legislative objectives on trade: a $300 million war chest to fight export subsidies of other countries, authority to negotiate a new round of global trade talks, looser antitrust laws to make American companies more competitive internationally, and tighter controls against pirating of U.S. patents and trademarks.

Beyond that, he said, the White House would accept some strengthening of laws against unfair practices.

"Obviously, what has been introduced goes considerably beyond that," Yeutter said. He added that the administration has no hope in dealing with the House "because the process has been politicized there," but said, "Perhaps we can make progress in the Senate."

Yeutter has been fighting an uphill battle within the Reagan White House over the need to deal with Congress on trade legislation, administration sources said. He and Commerce Secretary Malcolm Baldrige favor trying to develop a trade bill that eases congressional frustrations without compromising the administration's free-trade ideology.

But they have been outvoted in the Cabinet, with the opposition led by Treasury Secretary Baker. He told the senators Tuesday that administration moves to lower the dollar to use existing laws against unfair trade practices were enough to lower the deficit.

Heinz, meanwhile, criticized the Reagan administration for "giving away the store" in past trade negotiations, and said he is not sure Congress should give the White House authority for new trade talks.

"Our successes have at best been damage-limiting and our failures have been disastrous for many industries," said the Pennsylvania Republican, whose state's industries have suffered from surging imports and dwindling overseas sales.

Commerce Undersecretary Bruce Smart, however, told a New York audience yesterday that "the biggest cloud on the trade horizon" is the possibility that a tough trade bill will pass Congress and derail administration efforts to get a new round of trade talks started.