A process for magnetizing multiple magnetic circuits. The process comprises the following steps: S1, fixing an un-magnetized internal magnetic circuit assembly (12) to an un-magnetized external magnetic circuit assembly (22), so as to assemble into an un-magnetized magnetic circuit assembly (32); and S2, magnetizing the un-magnetized magnetic circuit assembly (32) that is completed in the Step S1, in this step the un-magnetized internal magnetic circuit assembly (12) and the un-magnetized external magnetic circuit assembly (22) are magnetized respectively by using an internal magnetic circuit magnetizing coil (40) and an external magnetic circuit magnetizing coil (50), so as to complete the process for magnetizing multiple magnetic circuits.