ON THE FACE of it, the present revolt by Congress against the new Social Security tax law - its own work - is an oddity. In December, Congress voted to increase payroll taxes far into the future. In January, under earlier legislation, the payroll taxes went up. For a person with an above-average income, it amounted to an additional $105 a year out of the paycheck. That's not an insignificant amount. But neither was it unexpected and, extracted at the rate of a couple of dollars a week, it does not rank among this world's greater burdens.

Now a deluge of public wrath and resentment has rolled down upon congressmen who, full of anxiety and penitence, are scrambling wildly to undo last December's bill in the few remaining months before the fall election. Why this sudden and disproportionate reaction to the increase in the payroll tax? It was, after all, only the latest among many, and most have arrived almost without comment.

The reason for the outburst, we suspect, lies in the way that Congress trumpeted its intention last year of shifting more of the load onto the middle classes. For people who earn over $20,000, the burden under the new law will be a good deal more severe, in the 1980s, than it would have been under the old law. Congress needed money for the pensions, and got it maily by accelerating the rise of maximum income on which the tax is collected. The Social Security payroll tax is collected, remember, on the first dollar that you earn, with no exemptions or credits - and on every dollar up to a limit that was $16,500 last year, but is $17,000 this year and will keep rising rapidly in the years ahead. It was the deliberate and well-advertised purpose of Congress to shift upward the delicate balance by which the weight of this country's various taxes are divided among income levels.

That's a sensitive matter. As the system now works, nearly all Americans carry about the same burden. When you take all the taxes together - federal, state and local - they come out to just about one-third of most people's income. The only great exceptions are the very rich and the very poor, both of whom pay more.The income tax hits above-average incomes hardest; the payroll taxes bear most sharply on below-average incomes. Sales taxes are regressive, the degree depending on exemptions that vary from one state to another. Real-estate taxes are, except for the elderly, roughly proportional to income. But when you add them all together, it works out to an astonishingly uniform rate across a very wide range of incomes. When Congress voted last December to raise the payroll taxes rapidly to include most middle-class income, those taxpayers saw it as a purposeful assault on them. They were being picked on. The basic balance was being shifted against them.

But if that Social Security law was a political mistake, Congress is now on the verge of compounding it with a far greater one. Whatever its defects, the present Social Security law is a serviceable and tolerable solution for the present. The alternative is to try to rewrite it, in frantic haste and controversy, in the summer before an election. Worse, there is now a proposal to link the Social Security system to the president's energy bill, by using its crude-oil tax to pay for pensions. The energy bill, as you may have noticed, has not made much progress lately. Congress, in its desperation, is about to link two of the nation's intractable issues to each other. Does that sound like a formula for achieving a fair and judicious tax law quickly?

Still worse, by reopening Social Security taxation now, Congress would inevitably get it entangled in the president's income-tax reduction bill. That tax reduction is needed urgently to protect the stability of the economy over the next year or two. It would be wanton, at this very late point in a short session, to undertake a complex and confused attempt to redefine the basic pattern of taxation in this country. The wise thing for Congress to do is grit its teeth, pass a clean and simple income-tax cut - and leave Social Security to next year.