A camera lens cleaning system includes a camera, a cleaning device, a processing unit, and an executing unit configured to move the color testing disk and the cleaning device. The camera is used to capture a plurality of different color images of a color testing disk located below the camera. The processing unit is used to process every adjacent two different color images to obtain a difference color value; thereby the processing unit compares the different color value with a reference color value to determine whether dirt is located on a camera lens of the camera. When the dirt is located on the camera lens, the executing unit is configured to move the cleaning device to clean the camera lens. The disclosure further offers a camera lens cleaning method.