An acousto-optically Q-switched vortex Nd:YAG laser by annular pumping of circular Dammann grating (CDG) shaping is investigated. The cavity of the laser is composed of a laser crystal, an acousto-optical modulator and a planar output coupling mirror. The pump source is a fiber coupling semiconductor laser of 808 nm. The annular intensity distribution of pump light is formed by the first-order diffraction of a CDG with high diffraction efficiency, which is used to end pumped Nd:YAG laser crystal. The octive Q-swith pulse laser is obtained with high optical quality, linear polarization and spiral phase. The obtained power of laser pulse is 470 mW, the peak power of laser pulse reaches 588 W and pulse width is 160 ns, when the absorbed pump power is 5.6 W and the frequency of acousto-optical modulator is 5 kHz.