The invention discloses a high-precision joining method of an uneven surface object picture. A coordinate in a world coordinate system of a plurality of sampling points on an uneven surface object is obtained by utilizing three-dimensional scanning according to an overlapped area of a first image and a second image to be joined, the coordinate is fitted in a least square method to obtain a best re-projection plane, and a best re-projection coordinate system is established; the coordinate of each sampling point in the world coordinate system is converted to a coordinate in the best re-projection coordinate system, and an error between an ideal image coordinate and a real image coordinate of the sampling point is calculated according to the internal and the external parameters of a camera; the error between the ideal image coordinate and the real image coordinate of all pixels in the overlapped area is obtained through interpolation; the first and the second images are corrected so as to obtain and to join the first image and the second image with no error. Pin-hole model simulates imaging of infinite focal-length lens, which is followed by the imaging of the camera, so the generated picture eliminates the joining error caused by the uneven surface perspective projection.