Orman S. Fink, 75, minority staff director of the House Banking Committee for 30 years and a specialist on banking, finance and parliamentary rules, died of cardiac arrest Tuesday at Arlington Hospital.

Following his retirement in 1974, Mr. Fink remained with the committee as minority staff director on a yearly retainer until 1977, when he became senior adviser. He retired a second time last year for reasons of health.

Before moving to Washington in 1942, he worked in real estate, insurance and investments in Nebraska and Illinois. From 1942 to 1945, he was a legislative assistant to Charles Dewey, a former Illinois Republican congressman.He then served on the Herter Commission staff, helping to administer the Marshall Plan, until 1947, when he joined the banking committee.

Mr. Fink was born in Holdrege, Neb. He graduated from Grinnell College in Iowa, earned a master's degree in business administration from Northwestern University and attended the Guaranty Co. of New York Bond School. He was a member of Phi Beta Kappa.

His wife, June Marie, died 26 years ago.

Survivors include a daughter, Barbara Lee Vollmecke of St. Louis; two sons, Daniel F., of Corona, Calif., and William O., of Beatrice, Neb., a sister, Ruth E. Horton of Sibley, Iowa, and five grandchildren.

The family suggests that expressions of sympathy be in the form of contributions to the Northern Virginia Retarded Citizens Association in Falls Church.