In the process of geometric model processing by mesh generation software, a filling method based on B-spline surface was proposed to solve the hole problem caused by missing geometric surface information. The hole boundaries were extracted from the given set of B-spline curves based on their topological relationship, and curve approximation fitting and combination techniques were employed to process the curves within individual holes to obtain compatible curves. Hole repair was achieved by first constructing unidirectional interpolating ruled surfaces and tensor product surfaces from the curves, these surfaces were then combined through interpolation and Boolean sum operations to generate bilinear difference B-spline surfaces for filling the holes. In addition, the ruled surface was applied as an alternate method in complex special holes to ensure the overall robustness of the method. Experimental results show that the method is highly general and can be applied to the dirty geometry repair of various types of morphological holes in real-world industrial geometric models, providing clean and closed geometric models for subsequent mesh generation.