In order to improve the accuracy and smoothness of reconstrucing fault planes with sparse data, a method for building fault plane model is put forward. The method analyzes and selects the fault level modeling data, then uses Morphing method to construct transition curves of adjacent sparse fault lines, and at the same time, uses CD-TIN to reconstruct smooth fracture surface. Based on the basic theory of Morphing method, the correspondence of feature points of fault line data is analyzed and feature points' matching is realized by distance dichotomy. With reference to the finite extrapolation method, the location of the fault tip is determined. The method of Lagrange interpolation is used to extrapolate the curve of node of fault line and realize the cutting of intersecting fault plane. And the smooth construction of broken layer under sparse data is realized. The forms of fault plane model generated by Kriging interpolation method and Morphing method are compared. It is concluded that the fault surface formed by Morphing method is smooth and natural, and it can better restore the bending details of the fault.