In order to improve the large- scale curved surface parts machining accuracy of five axis machine tool, a new method using laser tracker to identify quasi- static errors of rotary axis is proposed and a compensation experiment is also implemented. the error model of rotary axis is established based on the rigid body kinematics and at the same time the errors of perpendicularity between the rotation axis and linear axis are also given. Different circle paths are designed in different planes and spatial coordinates of four positions are measured. Some equations including all the error components of rotation axis are established and the error components can be obtained by solving the equations. The perpendicularity errors between the rotation axis and linear axis are obtained through the relationship with the fitting center of two following circle and linear axis. The proposed method is applied to a double swivel head spindle five axis machine tool for error measurement and compensation. Experimental results show that this method is quite convenient and effective.