Former vice president Walter F. Mondale charged today that "disarray" in the Reagan administration is jeopardizing chances for disarmament and economic recovery, and Sen. Alan Cranston called himself the Democrats' "peace candidate" as he sought crucial home-state support for his presidential campaign.

They were in the vanguard of seven Democratic presidential aspirants at the annual California state Democratic convention. Each will address it Saturday and solicit support from the more than 2,000 delegates and alternates.

There will be at least one measure of that support. The Los Angeles Times is polling the delegates on their presidential preferences. The convention will vote first thing Saturday on whether the California party should conduct a poll of the convention of its own.

Despite the damage a loss here would do to his embryonic campaign, Cranston has pushed hard for the poll, convinced that he needs such an early show of strength to give his campaign credibility.

He has campaigned hard, contacting more than 1,000 delegates in person, and is favored to win. Thursday he met with the Democratic leaders of the assembly to urge them to support the poll.

The drive for the poll is being led by Howard Adler, chairman of the Orange County Democratic Central Committee, and Richard O'Neill, former state Democratic chairman.

O'Neill said that if Cranston lost "it would be the end of him."

Cranston ranks far behind Mondale and Sen. John Glenn of Ohio in national polls for the Democratic nomination, but he has collected endorsements of his candidacy from nearly all of California's Democratic Party leaders.

In addition to Cranston, Mondale and Glenn, Sens. Gary Hart of Colorado, Ernest F. Hollings of South Carolina, Dale Bumpers of Arkansas and Rep. Morris K. Udall of Arizona are scheduled to attend the convention and a host of related receptions, meetings and parties.

Former Florida governor Reubin Askew declined an invitation.

The Times' straw poll, which isn't even on the convention's formal agenda, and the potential party poll, are the main points of attention.

Cranston insisted that he was "not a favorite-son candidate, I am a national candidate," and that he was second only to Mondale in national fund-raising and campaign staff.

Cranston told reporters that he felt the "only real obstacle" to his winning the nomination in 1984 is name recognition and that it "will not be difficult to overcome that" with his campaign organization and fund-raising.

Cranston also said he thought his candidacy would be helped if a pending proposal to move California's 1984 primary from June to early March is adopted.

He said that while Mondale, Glenn and the other Democratic hopefuls all favor an end to the arms race, "what differentiates me from the other candidates is my absolute and total commitment to the attainment of nuclear peace." He added that President Reagan "does not comprehend the danger of nuclear war, and I have come to the reluctant conclusion that he is incapable of negotiating effectively with the Soviet Union to end the arms race."

Mondale challenged Reagan to "take charge of your government" before further damage is done.

The undeclared Democratic presidential aspirant said that "deterioration of presidential direction and authority" was sending shock waves through the nation and the world.

Mondale urged Reagan to meet with Soviet leader Yuri V. Andropov "at the earliest possible moment" to reduce tensions in the world, which he said had grown seriously since Reagan became president.

Mondale, who starts 1983 out in front of the Democratic field, said the country could not wait for the 1984 election for leadership to face its problems.

"For a year," he said, "it has been evident" that Reagan's plea to "stay the course" was falling on deaf ears.

Arguing that the "signs of unraveling are everywhere," Mondale said this week's shakeup in the Arms Control and Disarmament Agency was "inexplicable."