In order to realize rapid measurement on blade of large water turbine, a new approach based on photogrammetry was proposed and implemented. The working procedure of the new method is divided into several phases: First, paste reference points on the surface of the object, and then, take a group of pictures from different view as 2D original data. Once these pictures are loaded on the measurement software XJTUDP, it begins to inspect each picture, detect and locate the reference points. Finally, according to their 2D coordinates on different pictures, 3D coordinates of the reference points are reconstructed, which in fact are the different projection of the same reference points. As a result, a great deal of 3D reference points form the model of the object. Consequently, further measurement about the exterior dimension could be carried out. Experiment result shows that, compared with traditional methods, the new method is timesaving, low cost and can be applied on-line measurement easily. Furthermore, it is immunity from dust, vibration, humidity and temperature variety.