A catadioptric step zoom lens for remote supervision TV is designed. Once imaging catadioptric step zoom is proposed so that three bands such as weak light,white light and near infrared share the same optical system. Theory is explained in detail and design examples are displayed in the paper. The disadvantages that the secondary spectrum of reimaging catadioptric step zoom lens can not be corrected are overcome. Moreover,the black spots generated in image plane center are avoided and the structure is simple.