Using resonator inserted with acousto-optically modulator, the experiments of the compacted CO2 laser are performed with Q-switch. According to various factors that influence the output of laser, the theoretical calculation of its main parameters are conducted by Q-switched pulsed laser rate equations. Based on the results, the technical route and approach are presented for optimization design of this laser. The measured peak power of the acousto-optically Q-switched CO2 laser is more than 4000 W and pulse width is 180 ns which agrees well with the theoretical calculation. The range of repetition frequency can adjust from 1 Hz to 100 kHz. The theoretical analysis and experimental results show that the acoustic traveling time of ultrasonic field can not influence the pulse width of laser so that it doesn′t require inserting optical lens in the cavity to reduce the diameter of beam. The acoustic traveling time only extends the establishing time of laser pulse. The optimum working frequency of laser is about 1 kHz, which it matched with the radiation life time (1 ms) of CO2 molecular 0001 energy level. When the frequency is above 1 kHz, the pulse width of laser increases with the frequency. The full band of wavelength tuning between 9.2 μm and 10.8 μm is obtained by grating selection one by one which the measured spectrum lines are over 60 in the condition of Q-switch.