The AFL-CIO yesterday gave its approval to the NFLPA strike at an elaborately staged press conference here in which union leaders expressed solidarity with the striking players.

"We will do all in our power to help the players reach a just, equitable and speedy settlement of this dispute," said AFL-CIO President Lane Kirkland in a letter read by Thomas Donahue, secretary-treasurer of the 14.9-million-member labor union.

William H. Wynn, president of the 1.3-million-member United Food and Commercial Workers Union, the AFL-CIO's largest affiliate, said the players "having been thwarted by the rejectionist reactionary approach of their employers . . . have democratically and overwhelmingly exercised their rights as American workers to strike to get their fair share of the revenue produced through their skills, talents and efforts over what is, unfortunately, too short careers."

Should the NFL attempt to play with nonstriking players, Wynn said, he would ask his members not to attend games and not to work at stadiums.

Six players attended the AFL-CIO press conference at the union headquarters on 16th Street NW, including Redskin running back John Riggins, who showed up in a jungle commando outfit, complete with combat boots. Riggins said he was in charge of union "surveillance squads," which would monitor subversive activity around the league.

"I've been through this once before," Riggins said. "It's good to have 1,500 guys with me." Riggins sat out the 1980 season in a contract dispute with the Redskins.