The embodiments of the present invention provide an automatic monitoring method and a device for the limping of a broiler chickens. The method comprises the following steps: collecting the video images from the overhead of an active channel of broiler chickens who pass through the active channel; processing the video images to extract the distance information from the preset pixel points on the broiler torsos in the video images to the image collector; using the distance information to determine the postures of the broilers; and evaluating the limping behaviors of the broiler chickens according to the posture indexes to obtain an evaluation result. According to the method and the device for automatically monitoring the limping of broiler chickens provided by the embodiments of the present invention, the video images of the broiler chickens are acquired from the overhead of their active channel activity channel and the video images are processed to obtain the posture indexes of the broiler chickens so as to realize the automatic monitoring of the limping behaviors of the broiler chickens. This reduces the monitoring difficulty and the labor intensity for the monitoring of the limping of broiler chickens.