The methods and devices of a multi-functional operating interface for a care-taking machine. The multi-functional operating interface of the care-taking machine includes: muscle stretch sensor, multiplexer amplifying wave filter, analog-to-digital signal converter, image processing unit, and muscle pattern database and control bus. Aided by the present muscle template training method and potential image data collecting and processing method, it can become an interface that offers the user of a care-taking machine instantaneous and unlimited controllability of the machine, enabling such people, either sick or handicapped, to enjoy more convenience and better life.