An active-passive double Q-switched 946 nm laser was reported which with a double 45° cut-magnesium oxide doped LiNbO3 electro-optic crystal and a monolayer molybdenum selenide saturable absorber. In order to obtain 946 nm laser pulses with high energy and high peak power, a pulsed laser diode side-pumped long Nd∶ YAG rod is used as the gain medium in a folded biconcave cavity. Output pulses with maximum pulse energy and peak power up to 3.15 mJ and 346 kW were obtained, corresponding to 550 Hz repetition rate and 9.1 ns pulse duration at 946 nm. Peak to peak instabilities of pulse width and pulse energy were ±2.87% and ±3.42%, beam quality factors were Ｍ2x＝3.851 and Ｍ2y＝3.870.