A test system for testing a camera module is provided. The camera module includes a voice coil motor and a lens received in the voice coil motor. The test system includes a first focus activating unit, a second focus activating unit, and a timing unit. The first focus activating unit controls the voice coil motor to drive the lens to move from the initial position to the focusing position for achieving a first time focus and obtains a control signal. The second focus activating unit controls the voice coil motor to drive the lens to replace to the initial position and then move the lens from the initial position to the focusing position again for achieving a second time focus. The timing unit records a first moment when the lens is replaced to the initial position and a second moment when the lens is at the focusing position again.