Effective learn from design ideas and intentions of the design history product are important for similar new product development, so design intent capture of historical product is the key issue in this process. Method of reverse solving in product design history based on effect synthesis is presented. Action-unit model of design history is built for reversing seeking the principle solutions by effect synthesis. The function-units are generated by principle synthesis and functions replacement, also function structures are built to capture the design intent of design history according to the logical relation of input-output of energy flow, material flow and signal flow. A prototype system for inverse solving of design history product is developed and effectiveness of the above methods is verified by the engineering case.