The paper mainly discusses the design of a simplified operating lamp structure——an increase color temperature reflector with wide incident angle. We analyze the spectrum requirement on surgery light by using vertical triangular interpolation calculate color temperature and Tristimulus calculate color-rendering Index. And by comparing one result of an ordinary thin film, we optimized the design of on the film and shape of the reflector and designed a new color temperature reflector with wide incident angle. And the color rendition of the new design is even better when the incident angle changes in a wide range.As a result, the design of thin film decreases the complexity of the surgery light structure and enhanced the applying efficiency for the light which can be used as a replacement of traditional operating lamp structure.