Abstract: Exponential explosion during the process of disassembly sequence generation has become a bottleneck for a long time due to over large number of parts included in the product. To solve this problem, an approach based on the modularization is proposed in the paper to generate the disassembly sequence. In the approach, we construct a modularization disassembly model where the Hierarchy Network Graph of product is created automatically. The precedence constraints related to the hierarchy network graph are analyzed, and the process of generating the disassembly sequence is described. A case study is also given to show that the method is feasible and effective.