Optical system design of multispectral camera based on liquid crystal tunable filter(LCTF) was presented. The optical system has a focal length of 60 mm, F number is 3.5, spectrum band is 400～720 nm, and the field angle is 16.6°. It consisted of the fore-optical system and the subsequent imaging system, the fore-optical system was adopted in order to attain beam of light which can fulfill requirement of the aperture and field angle of LCTF, the double Gaussian structure was adopted in the subsequent imaging system. The imaging analysis results show that the design fulfills operating and engineering requirement. The optical system can produce a clear image in 16 waveband of the spectral range.