High power and good beam quality of solid laser has potential applications in modern industrial processing and scientific research, while the parameters of laser are affected by the dynamic thermal distortion caused by the thermal effect in solid state laser. Taking wave front distortion of the laser and advantage of the conduction cooled end-pumped slab (CCEPS) as a starting point, the wave front distortion caused by thermal effect in the CCEPS is measured by use of Hartmann-Shack wave front detector. By the analysis of results in the measurements of the aberration in the CCEPS, when the output power is different, the dynamic thermal distortion is obtained.