It is time for those who know better to stop frightening millions of Social Security beneficiaries with scare talk about the system's going broke.

Social Security does warrant attention. There are a number of changes and refinements that could bolster it, but it is irresponsible to yell "fire" in order to win support for hacking at the system's problems, all of which can be constructively resolved with little or no harm to the retirees.

Despite all the dire warnings that retirement funds may run out in the next year or so, there is no real danger that payments will be cut off. Congress would not dare let that happen. Nevertheless, many retirees and near-retirees have been needlessly upset.

Sen. Daniel P. Moynihan (D-N.Y.) accuses the Republicans of conducting "a campaign of terrorism" by exagerating the situation to frighten Congress into taking extreme action.

President Reagan, in turn, accused House Democrats, who have been fighting to preserve the minimum benefit, of "opportunistic political maneuvering, especially designed to play on the fears of many Americans."

Speaker Thomas P. O'Neill's prompt rejoinder was that Reagan was "distorting the issue." It is unconscionable, he said, to "exploit fears" about the condition of the system "so as to make deep cuts in benefit levels."

That there is widespread uneasiness has just been confirmed by a nations CBS-New York Times poll that shows 54 percent of the American people today doubt the Social Seurity system will have the money to pay the full benefits they are entitled to. Moreover, even among those already receiving benefits. 37 percent fear the system will not be able to cover its obligations and 26 percent believe their own benefits will not continue because of a fund shortage.

At the same time, however, the polls again demonstrated how strongly the people support Social Security. Even if a tax increase becomes necessary, 66 percent said, they would favor it. Only 27 percent were opposed. Congress showed it is well aware of this sentiment when the Senate voted unanimously to reject a package of benefit slashes sought by the administration and the House later voted 405 to 13 against the administration's proposed cuts in minimum benefits.

The continuing popularity of Social Security is remarkable, considering all the attacks that have been made on it over the years, especially charges that it is a "rip-off" and doesn't deliver as well as European retirement systems.

Actually, the U.S. worker, compared with workers in other leading industrial countries, has a much lighter Social Security tax burden. The employee payroll tax is now 6.65 percent in the United States compared with 12.04 percent in France, 16.4 in Germany and 23.42 in the Netherlands.

As for benefits figures for 1979 show a typical U.S. $15,000 a year worker, with a dependent wife, gets $8,780 annually. In France, it was $6,629 for a couple, and in Germany a retiree got $7,352 but nothing more for a dependent wife. In most of these countries, retirees got some additional benefits, but even so, the U.S. system is a comparative bargain.

Stanford Ross, former commissioner of Social Security, says he found in Europe a greater sense of "solidarity" between the elderly and young workers than he perceives in the United States. In Wester Germany and Sweden especially, he says, young workers "identify with the need to support the elderly and the handicapped," and the elderly are "concerned about the burdens placed on the young."

Doubts about the future of Social Security have been largely inspired by emphasis on the supposed threat of a shrinking work force and an expanding army of retirees. Today, for every person over 65, there are three between 18 and 64. In the next century, it is projected to be 1 for every 2. Thus, it is argued, we will end up with too few workers supporting too many retirees. Actually, the current ratio is considerably less than 3 to 1, for it treats all those between 18 and 65 as "wage earners," whereas millions of youngsters are now unemployed or still in school. It also doesn't allow for the fact that many elect to retire before they are 65.

The upshot is that the future change in the ratio will not be as dramatic as pictured. Also, a dwindling work force can easily be augmented by immigration, plus the addition to the work force of millions of currently underemployed women, plus the availability of many retirees who would welcome the opportunity to work under well-paid, full-employment conditions. So, in the decades ahead, there should be enough workers, to support the retirees comfortably.