The increasing of customer's individual requirements has brought forward a new problem to the mechanical industry. In this paper, the composing of customer requirements-driven product customization system, which can satisfy customer's individual requirements, and the key problems involved were researched, and during the researching, the construction machinery product was the example. The layered model of customer requirements and product structure was proposed, the GBOM (Generic Bill of Materials) model of the construction machinery product and the database of configure relation about the product was established too and the product customization system based on internet was constructed according to these. The tryout of the system in the enterprise had proved that this system not only can provide the product which the customer required, but also can greatly increase the processing speed of customer's order form and the manufacture efficiency.