Abstract: In view of the difficulties in obtaining structural parameters and determining blade curvature which are the key components of mine main fan for performance analysis, this paper proposes a reverse modelling method for digital extraction and design of surface feature points based on the theory of reverse design and through the study of model reconstruction principle and parametric modelling method. Firstly，the digital scanning and the fan blade surface characteristics data of data are pre-processing, and then it extracts the characteristics of cross section contour line, and analyse its curvature characteristic points recognition, the surface reconstruction are processed by generating section spline curve. Finally, the reverse digital reconstruction of key components of mine main fan are realized, which provides an effective solution for the problem without the key structure parameters.