The laser output characteristics of Ho∶YAP crystal are discrepant along different cutting directions. In this study, a-cut, b-cut, and c-cut 0.5% (atomic fraction) Ho∶YAP crystals were used to investigate laser output characteristics. Using a thulium-doped fiber laser with a central wavelength of 1915 nm and maximum power of 44.3 W to end pump the Ho∶YAP crystal along each cutting direction, continuous-wave laser power greater than 20 W was achieved. For the b-cut crystal, the central wavelength of the output laser is close to 2118 nm and the maximum continuous-wave output power and slope efficiency are 23.6 W and 61.98%, respectively. The results for the a-cut crystal are similar to those for the b-cut crystal, but the central wavelength for the c-cut crystal is 2129 nm when the maximum output laser power is achieved. When the Ho∶YAP laser operates in an in-cavity acoustic-optical Q-switched state, central wavelength shifting and multi-wavelength resonance occur in the a-cut and c-cut crystals. However, for the b-cut crystal, a stable pulsed laser output with a central wavelength close to 2118 nm can be obtained. For a pulse repetition rate of 20 kHz, the maximum average output power, pulse width, slope efficiency, and beam quality factor are 22.3 W, 20 ns, 55.22%, Mx2=1.81, and My2=1.50, respectively. From these results, it can be concluded that the b-cut Ho∶YAP crystal is more suitable for obtaining stable and efficient 2118-nm continuous-wave lasers and nanosecond-level pulsed laser output.