A day and night fisheye CCTV lens with wide spectrum is designed.The near-infrared LED light source is used to illuminate and the IR-CUT double filter is adopted.The near infrared wavelength is 850 nm.Using multi-configuration design of Zemax software，the confocal visible light and near-infrared light can be realized with a fixed focal length.The designed optical system structure and aberration curve are analyzed.The full field of view and relative aperture are 175°and 1/1.8 respectively，using 1/3 in CCD as image device.Full field of MTF value reached 0.3 in the spatial frequency of 100 lp/mm.