Because of the influence of the angle error, the atmospheric refraction and the error of the interpretation, the attitude angle calculated by the plane intersection method had some errors, and when the plane intersection angle was small, the result was even wrong. In this paper, through the interpretation of the direction vector of space target on multiple photo-electric theodolite target surface, the nonlinear error model was established, and combined with the least square method and L-M iterative method for solving the direction vector of the target in space to get the target attitude angle. This method could reduce errors or mistakes due to the small angle between the surface and the surface, and the calculation accuracy was higher.