In order to solve the contact profile scanner due to defective components are installed and the problem that the deviation caused by the result of the measurement data, this paper analyzes the main source of error, based on the idea of least square method, the minimum residual sum of squares as the optimization target processing error of the system model is established, and establish a set of based on LM algorithm iteration the field calibration method of system parameter, and using Matlab software programming algorithm is verified the feasibility and robustness of algorithm in experiments, simulation experiments data shows that the algorithm can realize accurate calibration of system parameters and coordinates of correction, fast convergence rate, High accuracy can control the measurement error below 0.05mm, Angle error control below 0.1°, greatly reducing the scanner's manufacturing and installation accuracy requirements.