An active q-switched solid-state laser with peak power,narrow linewidth and high beam quality is reported in this paper. It has the advantages of small size,compact structure and strong environmental adaptability. LD side-pumping and space-compensating,active RTP Q-switched,volume Brag grating technologies are used in the laser. At the working frequency of 20 Hz,the obtained pulse width is 10 ns,the single-pulse energy is 200 mJ,and the beam divergence angle is 2 mrad. At room temperature 25 ℃,the laser of center wavelength of 1064 nm,central wavelength drift≤0.05 nm，Δλ≤0.1 nm is obtained.