The invention provides a parameter identification method of a mechanical arm. The parameter identification method of the mechanical arm comprises the steps of defining an M-DH parameter, and writing out a homogeneous transformation matrix between joint coordinate systems; acquiring each theoretical joint angle value, substituting into a robot kinematics forward analysis model, and solving to obtain a theoretical terminal position and an error expression; measuring a practical terminal position, and solving an error value between the theoretical terminal position and the practical terminal position; measuring terminal positions of multiple groups of joint points, building a system of linear equations, and utilizing a least squares algorithm for solving an error value of the M-DH parameter;correcting the M-DH parameter, and utilizing the corrected M-DH parameter to obtain a corrected terminal position; and judging whether an error between the corrected terminal position and the practical terminal position is converged or not, and if yes, finishing the flow. The invention further provides a parameter measurement method and a parameter measurement device of the mechanical arm, a parameter identification device of the mechanical arm, a terminal device and a storage medium. By utilizing the embodiment of the invention, the parameter identification accuracy can be improved.