A new 360° panoramic imaging device is designed for cylindrical object inspection application. Through single viewpoint constraint, the shape of the reflective mirror is determined. According to the depth of field, resolution, field of view, etc. the parameters of the mirror are calculated. For a particular cylinder size, the optimum mirror satisfies the camera depth of field constraints and the system resolution reaches 80% of the original camera resolution. The device is simulated by optical design software to determine the optimal parameters according to the evaluation criterion of image quality. The captured image from the proposed device is unwrapped through a systematic calibration method to obtain the perspective projection panoramas. The designed reflectance mirror is simple, low cost, low distortion and high imaging quality. The proposed 360° panoramic imaging mirror design method and corresponding device overcomes the traditional cylindrical object imaging hardware equipment complex, expensive shortcomings, and provides a design method for machine vision.