The stray light of the infrared sensor consists of external stray radiation and internal stray light. The simulation analysis and suppressions of the stray light of the infrared optical remote sensor are very different from the remote sensors working in visible wavelength. The suppression of the internal and external stray light are usually contrary. However, the optimizing measures should be applied for the suppression of the external and internal stray light together. The conception of integrative suppression of the external stray light and internal stray light is introduced by studying the changing trend of the internal and external stray light for the same measure in different stes. In an example about the suppression of the stray radiation in an infrared warning camera, the characteristic of the key surface is analyzed and the best measure is adopted by the conception of the integrative suppression. The analysis results can satisfy the requirement of the system.