Prominent Soviet dissident Yuri Orlov will go on trial here Monday for anti-Soviet propaganda, friends said yesterday, becoming the first of the three best-known human rights activists to be tried since the Kremlin crackdown began last year.

Orlov's arrest in February 1977 brought expressions of concern from the White House. The nuclear physicist has been held virtually incommunicado ever since, undergoing interrogation and more recently, apparently reviewing the file of charges compiled against him.

A diminutive energetic man of 52, Orlov founded a Moscow group in 1976 to monitor Soviet compliance with the human rights guarantees of the Helsinki accords signed by the Kremlin in 1975. The so-called "Helsinki monitoring groups" has since issued more than two dozen reports of alleged abuses of human freedoms here, including denial of permission to emigrate, on the one hand or forced emigration on the other, religious discrimination and the use of psychiatric hospitals to detain dissidents.

The KGB secret police have arrested more than a dozen dissidents since the spring of 1977, bringing an outcry from the West which, in turn, spawned bitter Soviet denunciations of "internal meddling." The other prominent dissidents now imprisoned awaiting trial are Alexander Ginzburg and Anatoli Scharansky. Ginzburg headed a relief fund for political prisoners, using royalty money from Alexander Solzhenitsyn's works. Scharansky, a Jew who was refused permission to emigrate on alleged security grounds, was a spokesman for the Helsinki group.

It is widely thought in dissident circles that these two men will be brought to trial relatively soon after the Orlov trial.

Orlov originally was charged last June with anti-Soviet activity, but this was stiffened in February to anti-Soviet agitation and propaganda. The maximum penalty is seven years imprisonment and five years internal exile.

Scharansky's case has attracted perhaps the loudest outcry. He has been charged with treason, a capital crime, and the Kremlin has accused him of working for the CIA. President Carter has personally denied this.

The fortunes of the dissidents have sunk considerably from the first days of the Carter administration last year, when the president was outspokenly supporting their cause. Since then, there have been numerous jailings, dozens of activists have been forced to emigrate or face imprisonment, and heavy penalties have been handed down in several trials.