George P. Shultz was confirmed unanimously by the Senate yesterday to be secretary of state and is expected to be sworn in promptly as America's chief diplomat to a strife-torn world.

The 61-year-old Shultz was approved 97-to-0 after a brief debate following two days of testimony about his views before the Foreign Relations Committee.

Shultz succeeds Alexander M. Haig Jr., who resigned three weeks ago because of personal and policy differences that have not been officially detailed.

President Reagan, in a statement issued after the vote, praised the Senate "for its wisdom in approving, so decisively, the nomination" and said the action "augurs well for continued cooperation between the Congress and executive branch. . . ."

He also praised Shultz for an "articulate and convincing presentation" before the committee and called him "a man of exceptional character and qualifications for this vital position."

During the Senate floor debate, Sen. Howard M. Metzenbaum (D-Ohio) expressed "deep anguish" because of Shultz' dealings with the Arab world as head of the multinational Bechtel Group. Metzenbaum said he had decided to vote for Shultz despite a "pervasive Bechtel-Arab-Shultz connection" in the hope that the Arab connection would help bring peace to the region.

During the floor debate, most of the senators praised Shultz without reservation. Charles H. Percy (R-Ill.), chairman of the Foreign Relations Committee, said Shultz "has the potential to be one of the greatest secretaries of state of all times."