A laser diode-pumped high-efficiency widely tunable Tm:YAP laser with excellent comprehensive properties is reported. The output power is stable at a given pump power. Under the absorbed pump power of 12.95 W, the maximum output power at 2,010 nm is 5.16 W, corresponding to a slope efficiency of 45.5%. The generated beam profile is close to the Gaussian TEM00 near the maximum pump power. Furthermore, the laser working wavelength can be continuously tuned through optimization from 1,894 to 2,066 nm, which is the widest tunable range for Tm:YAP lasers to date.