Based on simulation of the influence of gamma nonlinearity of the projector on phase error, a method of phase error compensation for structural light measurement based on phase shifting is put forward. In this method, quadratic polynomial is used to approximate the intensity of the captured images, meanwhile least square fitting method is used to compensate the phase error, and in this way, system error caused by the gamma nonlinearity of the projector is reduced greatly. Because it doesn′t depend on environmental light, camera parameters or DLP parameters, this method has superiority in aspects of universality, complexity and calculation speed. Experimental results show that this method reduces greatly the phase error caused by the gamma nonlinearity of the projector. The average phase error is 5 times smaller than that before error compensation, meanwhile the bit error rate of unwrapping based on look-up table method is reduced 14.5 times.