A new method based on the drum surface is proposed to fit the dual-curvature glass. The drum surface is obtained from the automotive body cloud data with the kinematic equation using line element geometry and K-Local-RANSAC algorithm. Then the guide rail curve is obtained by the proportional function method based on the drum curve principle. At last, the motion deviation of the glass is analyzed and the maximum motion deviation is not more than 0.6mm. The results have completely achieved the engineering requirements, which prove that the method of fitting the glass and the guide rail is correct and reasonable.