The small business community must be strengthened to sustain a strong economy and maintain top military strength, President Carter said yesterday.

To help accomplish this Carter is expected to send to Congress his message on small business today urging the passage of a number of the administration's previous initiatives to aid business as well as a new proposal. The new legislation would establish a uniform policy on patent rights in federally supported inventions allowing small businesses and universities to retain patent ownership of their discoveries.

He also said that the 1981 budget will contain "funds for the nation's first women's business development effort," including special loan and technical assistance programs.

"At the root of the problem of governmental insensitivity is the popular misconception that small business is not a significant factor in our economy," Carter said in his message. "Viewed in the aggregate, there is nothing small about small business."

During his address before the small business group last night, Carter noted that many businesses may be hurt by recent international crises. Referring to the nation's troubles in Iran and with the Soviet invasion of Afghanistan, Carter said that "Normal trade and commerce have been interrupted in order to demonstrate vividly our abhorrence and condemnation of terrorism and military aggression against innocent people." The president added that as a result of his decisions curtailing commerce "There are economic costs. We are sharing those costs so the burden will not fall only on you or on American farmers or on any other particular group."

Carter's address last night kicked off the White House Conference on Small Business. It was one of Carter's few appearances out of the Rose Garden since the Iranian and Afghanistan troubles began.

The conference was billed as nonpolitical although small business fast is becoming a powerful political lobby whose members employ 56 percent of the work force and although this is a presidential election year. Carter used the opportunity last night to list policies his administration has fostered specifically to aid small business and a dozen others ranging from curbing inflation to his energy initiatives.

The conference is intended to focus not only on small businesses but on important entrepeneurial subgroups such as minorities, women and veterans.

It continues through Thursday.