Reverse modeling of large cavity blade was studied in this paper, including digital measurement, data processing and 3D model reconstruction. The stator blade surface is very complex, which has a large space curvature aerofoil structure. Its shape design has a great influence on the flow characteristics of the fluid. The blade has a cavity structure. It is difficult to measure the complete point cloud data by the conventional digital measurement method. According to the special structure of the vane, a reasonable measurement scheme and data reduction scheme are designed. The model is reconstructed and the innovation and improvement design cycle of the large stator blade can be shortened by the reverse modeling. Thus provides the basis for blade mould design and subsequent processing.