To help the disabled people eat, this paper proposed a AI meal-assisting manipulator via the detection of the open-mouth target. The YOLO_V3 algorithm was used to complete the construction of the mouth opening and closing state data set and model training, and the mouth state recognition model was successfully constructed and evaluated. The experimental results show that the model has a high recognition accuracy rate, accuracy rate and recall rate of the mouth opening and closing state. Finally, the application verification was successfully achieved by building a functional prototype of the meal-assisting manipulator.