A rotating locking mechanism and a vehicle lock employing same, and a locking control method; locking of a rotating output piece (1) is implemented by means of a stable triangular support structure between a first locking piece (2) and a second locking piece (3), the second locking piece (2) producing an effective constraint on the first locking piece (2) in both a locked state and in an unlocked state, thus achieving product locking and unlocking reliability. The entire locking mechanism is controlled by means of the same switch piece (4), such that the control process is more compact and effective. Incorrect locking operations during rotation of a rotating member are effectively prevented by means of the mechanical structure and the automatic control method; locking is highly reliable, use is simple and convenient, and the entire rotating locking mechanism can be sealed and fixed inside a vehicle lock housing for use in the transmission machinery of a bicycle, an electric vehicle, a motorcycle or even a lightweight automobile.