Abstract: As a coincidence rejection module in the detection system of the Lanzhou gas-filled spectrometer, the multi-wire proportional chamber (MWPC) is primarily used for the detection of heavy ions. Considering the energy loss of heavy ions in the entrance window material, a 1 μm thick aluminized Mylar film was selected to balance energy loss and pressure resistance. To reduce mechanical stress on the entrance window and extend the detector's service life, experiments were conducted under low-pressure conditions, employing both delay-line and charge-division methods for signal readout. The comparative analysis of the performance of multi-wire proportional chambers under two different readout schemes reveals that, under low-pressure operation, the charge-division method achieves an anode-cathode coincidence efficiency exceeding 90%, with position resolution better than 1 mm. Even at a pressure as low as 3 mbar, the charge-division readout maintains stable operation, with the best position resolution reaching 0.64 mm. These findings suggest that the MWPC using the charge-division method is more suitable for long-term stable operation in the Lanzhou gas-filled spectrometer experiment.