The high efficiency single-longitudinal-mode (SLM) Tm, Ho:YAP laser with ring cavity is proposed. The Tm, Ho:YAP ring laser was run on unidirectional operation using a Faraday rotator and a half-wave plate. A 0.2-mm F-P etalon was employed for wavelength tuning. SLM power could reach 231 mW with the slope efficiency of 23%, M2 factor of 1.12, and wavelength tuning range of 2053.62 to 2058.0 nm. This is the first report on the SLM Tm, Ho:YAP laser based on Faraday effect with high efficiency and tunability.