Abstract: In order to solve the problem of additive defects caused by temperature during the laser additive manufacturing process of airport fuel pipeline materials, the simulation model of the temperature field of the laser additive manufacturing airport fuel supply pipeline was established. The model considered the change of the material’s thermal properties with temperature and the latent heat of fusion. The incremental accumulation process of increasing layers in laser additive manufacturing was simulated by the birth-death element method. The results show that the shape of longitudinal section of molten pool is trailing, while that of cross section is "bowl". With the increase of laser scanning speed, the maximum temperature of the molten pool decreases, and the width and length of the molten pool decrease gradually. The temperature decreases gradually from the surface to the substrate along the thickness direction of the increasing layer, and the temperature gradient reaches a peak at the junction of the base metal and the increasing layer. With the increase of laser scanning speed,the temperature of this path decreases as a whole, and the peak value of the temperature gradient also decreases. Along the direction of increasing material, the maximum temperature on the surface of increasing material is increasing gradually, and with the increase of laser scanning speed, the overall temperature of the path decreases and the temperature distribution tends to be gentle.