In this thesis, the properties about synchronous active-active mode-locking technology,cavity length modulate technology,single pulse selecting technology with a novel method of active-active transient mode-locked pulsed laser were discussed. The single pulse selecting rate to 100% was obtained.The single pulse energy attains to 1.087 mJ,the energy variety not more than 3%,the pulse width less than 300 ps,the transient peak power is to 3.62×106 W,the outside trigger to lighting time dithering is ±15 ns.