Several Prince George's County police facilities, described by County Executive Parris Glendening as "an absolute disgrace," will be upgraded and moved into new or renovated buildings over the next three years in a $9.3 million improvement program, county officials announced yesterday.

The improvements involve moving the Hyattsville, Clinton and Seat Pleasant stations, as well as department headquarters and several divisions into new facilities, including two renovated school buildings.

Glendening said the improvements, financed by bonds already approved by voters, will transform police quarters that are "simply inadequate, overcrowded and unsafe," into "modern, adequate facilities."

The county will save $156,000 a year in rental costs by moving from leased space to county buildings, according to Glendening.

Under the improvement plan:

*The Hyattsville police station will be moved a block on Rte. 1 into a new building as part of the "Hyattsville Justice Center," a complex also slated to house state courts, probation and parole offices. Funding for the police portion of the complex -- planned for occupancy by mid-1987 -- includes a $500,000 state grant for a work-release facility.

*The Clinton police station will move to the former Crestview Elementary School. The building, which should be ready for occupancy by next September, will be shared with other public agencies.

*The Seat Pleasant Station will be relocated to the former Kent Junior High School in Palmer Park, which also will house headquarters, the police training academy, criminal investigations, inspectional services, the vice unit and the special investigations division. Occupancy is scheduled for June 1986.

*Police records, currently kept at the Seat Pleasant station, will be moved to the "combined communications facility" in Capitol Heights, where county emergency telephone operators are currently located. The building will be renovated to house the records by the fall of 1985.