An absolute planar magnetic-field-shared angular displacement sensor is proposed in response to the increasing demand for miniaturized sensors with a large ratio of inner and outer diameters in the industrial field. The sensor utilizes PCB (Printed Circuit Board) technology to design the stator part as a structure in which two sets of induction coils share the toroidal magnetic field generated by the inner and outer ring excitation coils, and the rotor part as a planar magnetic-field-shared structure. This paper describes the structure and working principle of the sensor, and simulation experiments are carried out to verify its feasibility. The experimental results show that the error of the sensor is − 46 ~ + 87 “within the pair of poles the error is − 127 ~ + 412” in the range of 0°–360°.