The application of 2 μm laser source is introduced, and the energy level diagram and absorption spectrum of Tm:YAP crystal are analyzed. A laser diode end-pumped Tm:YAP laser is reported. A high efficient 2 μm laser is attained at room temperature. The CW output power is 6.5 W with the laser diode output power of 19 W, the optical-to-optical efficiency is up to 34% and the slope efficiency is 47.5%. While acoustic-optical (AO) Q-switch is working at modulation mode, the output power of 2 μm at the repetition of 10 kHz is 5.4 W, single pulse width is 70 ns, optical-to-optical efficiency is 28% and the slope efficiency is tested to be 42%.