Amid a crowd of local Prince George's ministers and national Republican leaders, the Rev. Perry A. Smith III announced his candidacy yesterday for the GOP nomination for the 5th District congressional seat, declaring his move would create a true two-party system in the overwhelmingly Democratic county.

Smith, a Baptist minister who switched to the GOP in January, was promptly presented with a check for $5,000 by Richard Richards, chairman of the Republican National Committee, who dubbed the 48-year-old community activist "a super-good candidate" and a "shining light."

Until last week, Smith was faced with primary opposition by James M. Whitehead Jr., a 24-year-old aide to Rep. Jack Kemp (R-N.Y.). Whitehead announced last Thursday, however, that he would be seeking a state Senate seat instead, clearing the way for Smith to receive the Republican funds.

In announcing his candidacy, Smith criticized the Democratic Party for using "the Band-Aid approach" to social problems.

"Our world and our nation are sick but by no means beyond healing," Smith said. "Chasms exist between people because of racial, class and political differences. . . . No person or social order recovers from a severe malady through the use of Band-Aids."

Smith was part of a group of 12 black ministers from Prince George's County who defected to the Republican Party recently. They visited the White House in March, along with other black ministers across the country, to help President Reagan defend his administration against charges that it does not care about minorities and the poor.

Smith brushed aside questions about his support for specific Reagan administration policies, and said, "I do have problems believing the marriage of the public and private sector," would be sufficient to cure all the country's economic problems. "I think it's going to require a more active role on the part of the government."

Smith added, "I was delighted that Mr. Reagan and Mr. Bush made a 360 turn," on the issue of tax breaks for segregated schools.

Smith was introduced by State Party Chairman Dr. Allan Levey, who pointed out the Republican leaders who lined the walls of the reception room. They included Republican National Committeewoman Louise Gore; White House liaison Thelma Duggins; former State Sen. Dr. Aris Allen, who ran for governor in 1978, as well as numerous Republican candidates for county office. Levey said that U.S. Sen. Charles McC. Mathias had planned to attend, but couldn't because he was introducing the extension legislation on the Voting Rights Act.

Smith also was joined by many of the 12 ministers who joined him in switching their party affiliation in February. At that time, Smith said the group hoped to register 10,000 black Republicans. Figures provided by the county's Board of Elections Supervisors showed that, from February through April, 189 Democrats had switched their affiliation to Republican, and 37 previously registered without affiliation had chosen the GOP. In the same time, 59 Republicans became Democrats, however, and 49 nonaffiliated switched to the Democratic Party. The deadline for changing registration is May 14.

Smith angrily responded to a reporter's question of whether he switched his registration because of the promise of funds. "There was no discussion of funds at that point," said Smith.

Smith ran for the County Council on a Democratic slate with Rep. Steny Hoyer in 1971. If he wins the Republican primary, Smith would most likely face Hoyer in November.