The present invention relates to a method for improving precision of external reference calibration of a multi-ocular camera based on multiple identification plate images, in order to solve the problem that the modeling error is large caused by that the positional relationship between the multi-phase cameras in the existing three-dimensional modeling is not accurate. The method for using the high precision calibration to calibrate the low precision provided by the present invention, the direction error of the axial direction is calibrated through the single point displacement error so as to reduce the overall calibration error; according to the method provided by the present invention, more spatial calibration information is constantly collected, and the spatial calibration information is taken to calibrate coordinate origin information and compensate the direction axis error, so that the effect that the characteristic with the large error degree is compensated by the information with small error degree; by virtue of the method provided by the present invention, the calibration error of the two-phase camera is reduced from that the original error level of the direction axis can be determined by multi-point measurement to the error level that the origin position can be determined by single-point measurement; and the method of the present invention is applied to the field of camera calibration.