By applying a sample test method, phosphate glass filters were tested in the tropical ocean environment of Wanning and the tropical rainforest environment of Xishuangbanna. Through observations and statistical analyses of the corrosion rate, weight-loss variation, and surface morphology under the two experimental environments, the corrosion characteristics of the filter under different environmental conditions were studied. The test results showed that the corrosion law was the same for the filters in the tropical rainforest and tropical ocean. However, the corrosion rate of the filter in the tropical ocean was greater than that in the tropical rainforest. The corrosion rate of the filter without a film was higher than that of the filter coated with MgF2. This study has introduced a method for improving the anti-corrosion ability of filters.