Peter Bunyan, who worked as a PCSO in the Camborne Redruth area, has been dismissed from the police force, following his conviction for misconduct while in a public office.
The divorced 40-year-old was jailed for seven years at Taunton Crown Court, after being found guilty of eight out of 12 counts of misconduct.
A police disciplinary panel met on Wednesday and sacked him.
A spokesman said: "Following a disciplinary panel on Wednesday March 20, Peter Bunyan has been dismissed from Devon and Cornwall POlice without notice."
Bunyan had affairs with four vulnerable women before and during his police shifts and used the Criminal Information System to track down the phone numbers and addresses of women on his beat.
His seven-year-sentence included four years for the affairs and three years for the passing of information gained from a police database.