Challenges remain in carrying out assembly modeling research efficiently. The apparent weakness in effective description of assembly knowledge and information is one of the root causes of the current situation. This paper presents a model based on engineering assembly semantic approach to the problems associated with assembly modeling. This method effectively reduces computational complexity. The assembly connection graph (ACG) proposed in this research includes engineering assembly semantics, which provides an effective approach to express both geometric and nongeometric information. The semantic information model presented in the ACG offers useful information for designers to make right decision and complete the assembly design competently. Utilizing this process, complex and low efficient computation in the design process could be avoided. In this paper, an example of product assembly is provided to illustrate the effectiveness of the proposed modeling approach. Apply this model in author's own research, has shortened lead time, and insured the completion of the National 863 project on time.