A new pumping structure of laser gain media slab is proposed, the thermal wavefront distortion caused by the non-uniform temperature distribution of the laser gain media slab will be self-corrected in this structure, and the theoretical model of the transient temperature distribution is established to describe the pumping structure, the analytic expression of the transient temperature distribution of the laser gain media slab is derived from heat conduction equations. Numerical simulations of the temperature distribution within 10 seconds and at 60 seconds are given for N-31 Nd