An acousto-optically Q-switched CO₂ laser is developed to satisfy the requirements of research fields such as laser ranging,environmental detection,spacial communications and the mechanism study of the interaction between laser and materials. In consideration of the influence of various factors on the outputs of the acousto-optically Q-switched CO₂ laser,an optimization method to design the acousto-optically q-switched CO₂ laser is presented by using the theoretical analysis and calculations of the laser rate equations for the main parameters of laser outputs. Then,a verified experiment is undertaken. The experimental results show that the laser can offer the laser parameters in the pulse repetition frequency (PRF) of 1 Hz-50 kHz,a pulse width of 180 ns and a peak power of 4 062 W,which agrees with the theoretical results well. The results demonstrate that a miniature laser with high repetition rates, narrow pulse widths and high peak powers can be realized by optimally choosing an acousto-optically Q-switched crystal and rationally designing an optical resonator,and it can also realize the wavelength tuning and coding output by selecting the grating lines and controlling the TTL signals.