The invention relates to a self-adaptive light-source face identification machine which is provided with an optical-image limit structure and a self-adaptive light source. The self-adaptive light-source device includes an environment light sensor and a light-emitting light source. The environment light sensor is provided with a guiding structure and capable of detecting the light intensity of a specific area. The self-adaptive light-source face identification machine is capable of achieving the following effects: under different environment light conditions, the machine is capable of rapid identification; and the accuracy rate is high and the cost is low.