To address the limitation in measurement accuracy caused by phase mismatch in traditional single-reference signal demodulation methods, a dual-channel synchronous demodulation method is proposed to enhance the precision of a precision printed-circuit board (PCB）-based electromagnetic induction-type angular displacement sensor. By providing independent square-wave reference signals for the sine and cosine output signals of the sensor, this method achieves attenuation-free demodulation through phase matching, fundamentally eliminating the gain inconsistency induced by phase mismatch. Experimental results show that, compared with the conventional method, the proposed approach reduces the original full-cycle measurement error from ±0.0323 5° to ±0.007 6°, lowers the compensated full-cycle error from ±0.006° to ±0.003 4°, improves the dynamic range of the sensor output signal from approximately ［-16 001, 9 338］ to about ［-30 000, 30 000］, and enhances angular stability to 0.000 1°. This study provides an effective technical solution for improving the performance of high-precision PCB-based electromagnetic induction-type angular displacement sensors, offering broad prospects for engineering applications.