Labor Secretary-designate William E. Brock sailed through a two-hour confirmation hearing yesterday, winning unanimous bipartisan praise from the Senate Labor and Human Resources Committee and deflecting harsh Democratic criticism of Reagan administration labor policies.

Brock won hearty endorsements from the 14 Republican and Democratic senators attending the hearing, but the proceeding also turned into a preview of congressional battles over the proposed "subminimum wage," the record of the Occupational Safety and Health Administration and other issues.

Sens. Edward M. Kennedy (D-Mass.) and Howard M. Metzenbaum (D-Ohio) strongly criticized OSHA's failure to enact new standards for control of dozens of toxic substances and faulted the administration for cutting more than $1 billion in job-training funds. But both said they strongly support Brock to succeed Raymond J. Donovan, who resigned last month to fight fraud and larceny charges in New York.

Metzenbaum said the department was "in shambles . . . and the only decisions made are decisions to do nothing." Kennedy said that through personnel cuts, "aggressive and effective law enforcement has been brought to a virtual halt."

Brock sidestepped questions about whether he would reverse decisions such as OSHA's last week not to propose a federal standard requiring toilets and drinking water for farm workers.

"I will review this and all other decisions as soon as I am confirmed," he told Metzenbaum.

When pressed by Metzenbaum as to whether he personally believed such facilities should be available, Brock responded: "Yes, I do."

The committee chairman, Sen. Orrin G. Hatch (R-Utah), said he expected the panel to vote as early as today to send the nomination to the full Senate. Hatch said Brock had earned "worldwide respect" as U.S. trade representative and "gained an impressive reputation as a careful listener and conciliator."

Brock, 54, whose nomination was welcomed by organized labor after its generally stormy relationship with Donovan, is a former Republican National Committee chairman and also represented Tennessee for 14 years in Congress.

He praised the labor movement in his opening remarks, saying, "The labor community itself deserves considerable credit for the bold steps it has taken in recent years to institute procedures to reduce absenteeism and increase productivity . . . . In all my travels over these past four years, I have seen no labor movement so dedicated to freedom and free enterprise as our own."

Brock said his priorities would be to improve morale in the 18,000-person department, review OSHA and other law-enforcement programs and focus on "economic health and job creation."

Metzenbaum attacked the Reagan administration's proposal to reduce the federal minimum wage from $3.35 to $2.50 per hour for teen-agers holding summer jobs. He said there was no evidence it would create new jobs and labeled it the "McDonald's, Wendy's and Burger Chef Opportunity Act."

Brock said he did not consider the lowered wage a solution, but said it could help many youngsters get their first job.