A method for testing an autofocus function of a camera module fixes a camera module and at least two test members sequentially spaced at different positions on an axis pointing straight away from the camera. The camera module is controlled to focus and capture images of each test member and record driving currents of the camera module to achieve those focuses at those distances. When a sharpness of image of a test member reaches a preset threshold value a correspondence table between the driving currents and object distances is generated. An autofocus testing device is further provided.