This paper has designed a high effecient uniformly pumping and cooling reflector; Using dual YAG rods having consistent optical properties into which a 90° rotator is inserted, and special output mirror having a variable reflectivity coating forming an unstable resonator with a total reflection mirror, the output beam from resonator with near diffraction limit under high pulse energy is got; the amplifier also uses dual YAG rods into which a 90° rotator is inserted for decreasing thermal depolarization, by amplifying, optical isolating, beam expanding and phase matching, a high repetition frequency, high beam quality and high peek power is achieved. The following are details: 1) pulse peek power: λ1=1064 nm,P1=388 MW/p, λ2=532 nm, P2=158 MW/p; 2) pulse width: τ1=8 ns(λ1=1064 nm), τ2=6.8 ns(λ2=532nm); 3) beam quality: M2=1.62; 4) pulse repetition frequency: τ=61 Hz;5) continuous work time: t=20 min.