A Tm:YAP slab laser with double-end-pumped and high power under room temperature is introduced. With double concave cavity structure and optimizing pumping facula size, F-P etalon is inserted in the cavity to control laser wavelength. When pumped power is 164.4 W, 54.7 W continuous output power is obtained, the slop efficiency is 44.2% and the output wavelength is 1 938.8 nm. With the increasing of the power, the output wavelength only has 0.3 nm shift and the laser output for 0.18 nm narrow line width is realized. And the optical beam quality is measured when pumped power is 10 W, 25 W and 35 W, which is 3.5, 4.1 and 4.2 respectively.