The anti-jamming capability of seekers has been one of the most important performance indexes to appraise the missile. Anti-jamming strategies of ladar/infrared (IR) composite seeker are proposed for the common smoke-screen jamming. Based on the analysis of interference mechanism, the impact on transmittance and range is calculated with respect to IR channel and ladar channel, respectively. The anti-jamming strategies and available problems of IR seekers are analyzed, then the composite anti-jamming strategy with target range information is proposed.