A 2 μm pulsed laser damage threshold testing apparatus is set up according to the international standard ISO 21254, the surface laser damage threshold of infrared nonlinear optical crystal ZnGeP2 with different surface quality are measured, meanwhile, the influence of different laser parameters, such as pulse frequency, pulse width, etc, on the surface laser damage threshold testing results are analyzed. These testing results provide an important experimental reference to avoid laser damage to ZnGeP2 in practical use.