In this paper, the surface equation of involute curve and transition curve of point-line meshing gear transmission were derived according to the rack-type tool processing principle. On this basis, the contact trace equation was derived according to the transmission characteristics of point-line meshing gear and the conditions that the contact points of two gears must meet. By means of coordinate transformation, the axis deviation angle was converted into coordinate transformation matrix, and the contact trace equation of point-line meshing gear transmission considering axis deviation was derived. By measuring the coordinates of a contact trace on a pair of teeth of point-line meshing gear transmission, computing axis deviation angle was gotten, and then the gear assembly model was established based on axis deviation, tooth surface condition was obtained by simulation analysis of partial load position, compared with the partial load position in a test, the correctness of the contact trace equation of point-line meshing gear is verified considering axis deviation.