The invention discloses a cube position benchmark-based grating-type automobile shape detection system, and aims at solving the problem that automobile shape scanning is achieved by adopting a cube position benchmark-based grating mode. The cube position benchmark-based grating-type automobile shape detection system mainly comprises a cube target (1), a projector (2), a camera (3) in the target, a tripod (4), and a camera (5) outside the target. The cube position benchmark-based grating-type automobile shape detection system is small in occupied space, simple in structure, high in test accuracy, simple in operation, easy to install, relatively low in cost and reliable in performance.