Abstract: The reliability growth test of iodine pneumatic valve in COIL was actualized, including the discussion of reliability growth model, design of test scheme, and the data analyzing and processing. We proposed the reconstruction measures of iodine pneumatic valve seal assembly and implemented the reliability verification test. The test result shows that the reliability of iodine pneumatic valve has raised obviously after the reliability growth test. The reliability growth model based on iodine pneumatic valve was deduced, which could provide technical support for improving the working reliability of iodine pneumatic valve.