Using Cr:YAG and acousto-optic mode-locker jointly, the fiber coupling LD pumping Nd: YAG laser was actively-passively mode-locked. The output average power of passively mode-locked by Cr:YAG only, actively mode-locked by acousto-optic mode-locker only and mode-locked by Cr:YAG and acousto-optic jointly are compared and analyzed. The result shows good resolution to the low output energy and stability, and the mode-lock amplitude and energy fluctuation is less than , with the depth of mode locking of 100%, pulse width less than 410ps and output average power near 290mW.