For the application requirements for high precision infrared remote sensing imaging,a middle wavelength and long wavelength infrared remote sensing imaging solution with high resolution,high noise equivalent temperature difference (NETD) and large swatch is put forward.It can get the middle wavelength and long wavelength infrared radiation information of ground targets on sun synchronous orbit simultaneously,with the infrared range of 3～5μmand 8～12μmrespectively.The spatial resolution of the middle wavelength infrared spectrum is better than 5 m,and the spatial resolution of the long wavelength infrared spectrum is better than 10 m,swatch is greater than 20km,and the NETD is better than 60 mK.The technical parameters are optimized depend on NETD and modulation transfer function (MTF).The matching theory of cold shield on re imaging coaxial three mirror optical system is analyzed.Then the initial configuration parameters are calculated.Finally two dual band infrared re imaging off axis three mirror optical systems due to matching form of cold shield are designed.The matching result is estimated.