A reasonable initial structure can effectively reduce the workload and improve t he subsequent optimization efficiency in the design of aspheric system,especially the optical system with several aspheric surfaces.This paper proposes a method using simultaneous multi ple surfaces (SMS) principle to construct the initial structure.The aberration characteristics of the method in imaging optical system design are analyzed,and the design process of initial structure of aspheric optical system is proposed based on the analysis.Finally,a laser radar receiving optical syst em with working wavelength 850 nm,focal length 20 mm,relative aperture 1/1.6,field of view 40°,a nd total length less than 30 mm is designed by the proposed method,which verifies the feasibility of this method in determining the initial structure of aspheric optical system.