Embodiments of the present disclosure disclose a method and apparatus for detecting a braking behavior of a front vehicle of an autonomous vehicle. A specific implementation of the method comprises: extracting a vehicle image from a vehicle area in an image acquired by the image acquisition device; converting a color space of the vehicle image to generate a first vehicle image; setting a pixel value of a pixel point in the first vehicle image meeting any condition in a preset condition group to a first preset value to generate a second vehicle image; analyzing the second vehicle image to determine a candidate vehicle light area group; and detecting, based on the candidate vehicle light area group, whether a vehicle indicated by the vehicle image is braking, and generating a detection result. The implementation improves the detection efficiency for the braking behavior of the front vehicle.