In order to solve the problem of relatively weak protection of self-propelled anti-aircraft gun, the application and countermeasure of its active protection ability are discussed. By analyzing the increasing threat and inadequate protection capability that self-propelled anti-aircraft gun, 3 schemes, including upgrading smoke emission system, installing reactive armour, and using ammunition interception system, are proposed. Combine with AHP to compare the pros and cons of 3 schemes. This paper studies self-propelled anti-aircraft gun’s active protection from different angles and the conclusion is that upgrading smoke emission system is the best scheme. This study can provide a reference for improving the ability of self-propelled anti-aircraft gun’s protection.