In order to study the influence of process parameters on the quality of laser metal direct forming parts, the direct forming process of single-track single-layer GH3625 alloy was studied by orthogonal test. The influence of laser power, scanning speed, powder feeding speed and other parameters on the width and height of single-track single-layer forming cross-section was mainly studied. The forecasting model was proposed and confirmed. The results show that the process parameters such as laser power, powder feeding speed, scanning speed and so on are different in influence on forming cross-section. Among them, the influence of scanning speed is the most obvious. The experimental results show that the linear regression model obtained by Minitab software is effective.