The durability research on the filter media is of great significance. It is necessary to establish a laboratory test method on it in practical use. A new testing method is provided for filter media durability under corrosive gas condition in the paper. PPS is selected as standard testing sample and it is tested in SO2 gas. Under 1000ppm SO2 and 200°C condition, both warp strength and weft strength of PPS increase at the beginning and then gradually decrease with duration. And the decrease of weft elongation is obviously higher than warp elongation for PPS.