The Washington Cathedral launched a 10-year nationwide campaign last night to raise a $25.5 million building fund to complete the structure begun here 72 years ago. It is believed to be the largest church building fund campaign in the nation.

Of the total, 40 percent is ear-marked to pay the $8 million debt and anticipated $2 million interest-the result of serious overspending three years ago to complete the cathedral's have in time for the bicentennial.

The cathedral fund-raising committee, whose sponsors include former Persident Gerald R. Ford, Mayor Marion Barry and Sen. Barry Goldwater, also is seeking $8.5 million over the next decade to endow programs designed to relate religious principles to national and community problems.

The only cathedral building projects of comparable scope currently underway in America are the $14 million effort of the California TV preacher, the Rev. Dr. Robert Schuller, to build a "Crystal Cathedral," and the resumption of construction of the Cathedral of St. John the Divine in New York City. Projected cost for the latter is set at $9 million.

Church officials indicated yesterday that because of the massive debt they had little choice but to launch the fund-raising effort.

"We have to raise the money to pay the debt or we are in serious trouble," said the Rev. Canon Charles Perry, cathedral provost.

The campaign calls for raising $12.5 million for building by 1982. Additional first-phase goals of $2.5 million for program endowment and $500,000 to endow maintenance of the massive structure have been set.

That will enable the cathedral, Perry said, to pay off the debt and fund enough construction work on the cathedral's unfinished west front "so we can keep the crew together."

The cathedral's dwindling crew of stone cutters and stone carvers, who literally are a dying breed because there is no call in today's world for their unique skills, were forced to terminate their work on the structure two years ago because of the financial crisis.

Deep cuts also were made in program and personnel at all levels in order to balance the operating budget.

The fund campaign, had a 10-year overall building and program endowment goal of $36.5 millions.

The major construction items remaining budgeted at $12.5 million are the towers of St. Peter and St. Paul, flanking the rose window on the west facade.

The spending of large sums on church construction has sparked criticism-and some confrontations-in recent years. Episcopal diocesan offices in New York were picketed last year by demonstrators who faulted the plan to finish St. John the Divine instead of using the funds to alleviate human misery in nearby Harlem.

"It's an age-old conflict between the making of a cathedral as an edifice for the glorification of God, or saying you should use the money for the poor," said Perry. "That sort of criticism is always with you."

Bishop John T. Walker, who as Episcopal bishop of Washington has the ultimate responsibility for guiding plans for the cathedral, believes the cathedral has an important role in relieving human misery and righting wrongs.

"We are raising significant funds [in the Washington diocese] to help with hunger locally, nationally and internationaly," he said. At the same time, he continued, cathedral and diocese-both of which he heads-function in "an advocacy role . . . to try to solve the problems of the hungry."

While agreeing that hungry persons must be fed, he continued, "I am more concerned that we use the tremendous leverage a place like this has to bring about programs that help people to help themselves."

Campaign plans released last night call for raising, over the next 10 years, a $5.5 million endowment whose income would help finance an urban mission program, a program on Christian faith in the world and a special pastoral ministry. The latter, with the help of foundation funding, already is getting under way and will seek to meet the needs of the troubled among the 300,000 persons who visit the cathedral annually. CAPTION: Picture, A $25 million drive has been started to complete the 72-year-old Washington Cathedral on Wisconsin Avenue NW. Construction is on west facade. By Tom Allen-The Washington Post