Turbine blades play a decisive role in the performance of turbomachinery. The whirling milling process may provide a cost-effective way to produce blade surfaces. However, due to the low stiffness of blades, elastic deformation of the workpiece is often induced by the cutting force during the blade whirling process. In this paper, the elastic deformation in finish machining blades using a disk-shaped milling cutter on a 3-axis (C/Z/X) CNC machine is investigated. First, the process of the blade-whirling is briefly introduced. Then, the simulation model is established for analysis of the elastic deformation of the workpiece. Seven sections are made along the blade and twenty reference points are set in each section. By applying forces to these points, the deformations at the different location of the blade surface are analysed by means of simulation using the ABAQUS software. The deformation trend and the maximum displacements of the workpiece are identified, which is of great significance for improving the manufacturing quality and efficiency.