A surface slicing and reconstruction method for complex surfaces with trimmed boundaries and holes is presented in this paper, by which the negative effects of trimmed boundaries and holes can be removed and the quality of building grid generation can be improved. Firstly, the boundaries of slices are drawn on the surface. Secondly, the adapted polygon construction method is applied to obtain the topological relationships to recognize the slices. Thirdly, the interpolation and relaxation method is used to achieve uniform n×m regular samplings. Then the slices are reconstructed to get sub-surfaces independent of the original surface, on which the grids are generated to obtain sub-grids. At last, the sub-girds are combined and relaxed on the original surface. Several cases are delivered, showing that the grids are uniform, smooth and harmonious near the boundaries.