Missile warning satellite is an important part of space warning system. The development of space-based infrared missile warning technology of America such as defense support plan (DSP), space-based infrared satellite (SBIRS) and next generation overhead persistent infrared program (Next-Gen OPIR) is introduced. The operation system, performance parameters and technology characteristics of mid-infrared optical load in space-based infrared system are analyzed. And the operation mode of the space-based infrared warning system is analyzed. The development trend of space-based missile warning technology such as high and low orbit satellite networking, multi-band, long line array, large format detection and elastic system construction is proposed.