The present disclosure provides an automatic correction method and device for a structured-light 3D depth camera. When the optical axis of a laser encoded pattern projector and the optical axis of an image reception sensor change, an offset of an input encoded image relative to an image block in a reference encoded image is acquired, and then the position of the reference encoded image is oppositely adjusted upwards or downwards according to an offset change to form a self-feedback regulation closed-loop system between the center of the input encoded image and the center of the reference encoded image, so that the optimal matching relation can always be figured out when the optical axes of the input encoded image and the reference encoded image change drastically. Furthermore, depth calculation can be carried out according to the corrected offset.