Imaging technology based on Panoramic Annular Lens (PAL) is the most potenial imaging method,PAL-based imaging system with long focus and high resolution has complicated optical structure,structural design is the primary problem.On the basis of optical path structure and imaging properties of the PAL-based imaging system,the design method of PAL and realy lens was discussed in detail,single PAL and complicated PAL were modeled,the aberration characteristics between them were compared,and the optical path connection condition and aberration compensation project between them was analysed.In this design,image was received by CCD with small size through off-axis scanning,meanwhile,the feasibility of the scanning mechanism was stated.According to the requirement of distinguishing 250 mm object at 300 m,system focus and CCD type were chosen reasonably by calculating,and a set of technical parameters were determined.A high resolution PAL-based imaging system whose focal length was 8 mm,relative aperture is F/# 3.2,lateral field is 40°~100° has been designed finally,which consisted of three agglutination PAL and relay lens of 8 pieces and 6 groups,all surfaces were spherical and all field MTF at 80 lp/mm were higher than 0.5,illumination uniformity of image was higher than 0.95,f-θ distortion of all field was within ±3%.the design meets the usage requriement well.