Abstract: A innovatory avoidance adjust solid state laser was demonstrated.It used the directional prism as a reflector of the resonant cavity.With the prism reflector,the laser operats normally without special adjustment.The stability is the highest than other rasonant cavity.The divergence angle of laser beam is small.The laser energy of far-field is focus.The deflection angle allowed of the reflector is of ±20°.The laser rod shift of D/4 is allowed which D is the diameter of the laser rod.The divergence angle of laser beam is small than 3 mrad.The laser output energy 300mJ/pulse in the high repeatition of 100Hz with a Cr4+:YAG crystal as passive Q-switch,and the laser field distribution is homogeneous.