Oil pump, engine, cold start control method and vehicle

The invention relates to the technical field of engine cold starting, and discloses an oil pump, an engine, a cold starting control method and a vehicle. The oil pump comprises an oil pump shell, a pressure relief cavity is formed in the oil pump shell, a pressure limiting valve is arranged in the pressure relief cavity, and a pressure relief hole is formed in the oil pump shell. The pressure limiting valve comprises a valve body, a spring, an electromagnetic coil and an electromagnetic iron core, one end of the spring is connected with the valve body, the other end of the spring is connected with the electromagnetic iron core, and the electromagnetic coil is located on the side, away from the spring, of the electromagnetic iron core and arranged at intervals with the electromagnetic iron core in the circumferential direction of the electromagnetic iron core. And the axis direction of the electromagnetic coil is consistent with the extension direction of the spring. The valve body can move in the extending di