The utility model discloses a device for evenly mixing magnetic particles. The device comprises a brushless DC (direct current) motor, a motor seat, an eccentric shaft provided with a bearing, an even-mixing rotating shaft and an even mixing head, wherein the brushless DC motor is mounted on the motor seat, a rotating shaft of the brushless DC motor penetrates through the motor seat to be connected with the eccentric shaft provided with the bearing, the eccentric shaft provided with the bearing, the even-mixing rotating shaft and the even mixing head are sequentially connected, and the even-mixing head supports a reaction cup to rotate to realize evenly mixing. An elastic piece press mechanism is arranged, so that the reaction cup can be effectively prevented from popping out of an accommodating hole during even mixing; the device is simple in overall structure and convenient to mount and can be simply and closely combined with a magnetic separation system of chemiluminescence immune assay equipment to finish an even mixing function, and an even mixing system is not required to be arranged externally and separately.