Infrared Search and Tracking (IRST) system is, by longer detect range, fine camouflage and lower error probability etc., becoming the first above all airborne warfare equipments in modern battles. Stare focal plane array (FPA) coming out, liberates the optical design idea on this system thoroughly. A kind of pure refractive optics, which dispenses with opto-mechanical scan, improves detective method and finishes target tracking in a wider field of view. The fundamental idea and main strategy is developed. In optimized design, damped least squares method and adaptive procedure are used to get higher spectrum range, wider field of view, lower distortion and appropriate MTF. And the project of this integrated multi-sensor electro-optical system is validated by simulation results in CODE V and so on.