A flow gas low-pressure multi-wire proportional chamber（LPMWPC） with an active area of 180 mm× 80 mm has been developed for the flying time test of the recoil nuclei on super heavy nuclear experiments. The LPMWPC detector can be operated in single as well as double step operational modes. In the case of double step operational mode with a high gas amplification factor, signals from α-particles reside well above the electronic noise. The gas leakage rate and time resolution obtained from the α239Pu source are shown and discussed at the condition of 3 mbar Isobutane gas. It was shown that the time resolution was better than 2.9 ns at the best work condition, and the detecting efciency was larger than 98% at the low energy α particles. So the LPMWPC is fit to measure the flying time in the super heavy nuclear fragments experiment.
