The invention discloses a linear rotary motor and a displacement and rotation angle measurement method. The linear rotary motor is a two-degree-of-freedom and can simultaneously achieve linear motionand rotational motion; the linear rotary motor comprises a linear grating ruler and a coded disc grating ruler. Both the linear grating ruler and the coded disc grating ruler are arranged along the output shaft direction of the motor, so that the displacement and rotation angle of linear motion of the motor output shaft can be directly measured, the layout of the linear rotary motor is simplified,the control difficulty of the positioning accuracy of the linear motion is reduced, and the performance of the linear rotary motor is effectively enhanced.