The invention discloses a human body back spine midspinal line recognition method based on a depth camera. The human body back spine midspinal line recognition method based on a depth camera includesthe steps: acquiring a deep image of a human body back, performing meshing, performing curvature processing, extracting the midline area of the back, acquiring the coordinates of ridge points and thecoordinates of hipbone points, performing three times of batten interpolation fitting processing, and obtaining the midspinal line of the human body back. The human body back spine midspinal line recognition method based on a depth camera can obtain a complete human body back midspinal line so as to improve accuracy of extraction of the midspinal line by performing curvature processing on the human body back deep image, extracting the human body back information and processing the part of the extracted midspinal line through three times of batten interpolation fitting method.