Abstract: Abstract: In order to adapt to the dynamic changes of market demands, the ecological relationship of food chain was introduced into product conceptual design, the relations of products are systematically classified at a cognitive level as competition relation and symbiotic cooperation relation. These relations laid a foundation to systematically realize the spirally guide by double threads. Products need evolving from low level to high level to gradually adapt to the dynamic change of market environment which is similar to biological evolution, so products were classified based on the market, and product evolutionary chain and product symbiotic ring were built from junior to senior in accordance with the food chain relationship. Products in the process of evolution present the dynamic characteristics of spiral evolution under the dual function of radial symbiotic ring and axial evolutionary chain at the same time, the design methods and models guiding product evolution by double threads of competition and cooperation was put forward based on the analysis of the dynamic product evolution information. Applying components control template method between design objectives and competitors, In both applying properties related template method between design objectives and symbiotic objectives, the whole process of evolution design was guided by the competitive information and symbiotic information in the model, which make products evolution purposefully. This paper implement the testing and pushing of evolution degree step by step based on the evolutionary genetic algorithm, which guaranteed the rationality and adaptability of each product layer evolution process in the model. According to the practical innovation design conditions, the competition effect and symbiotic role in the process of evolution. The model spirally guided by double threads can dynamically and flexibly yield a total evolutionary scheme feasible for the desired product. The model spirally guided by double threads can systematically investigate product factors and the actual design environment factors outside, which can make the innovation design scheme better feasibility and performance guarantee because of the comprehensive consideration of the environment, the model not only can dynamically generate a suitable product innovation principle scheme model, but also can orderly and reasonably guide designers to carry out the product innovation design. To effectively and systematically realize the evolution computerized, this article also put forward the system architecture of product evolution spirally guided by double threads, input the product evolution information by two evolutionary mechanism of self-trigger and designers-trigger, and achieved product evolution design through the evolution model spirally guided by double threads, after the completion of the design at the same time fed back the product information to the system preparing for the next innovation, the information circulation in the system made full preparation for product dynamic evolution continuously，in which the proposed dynamic evolution theory of product information and system frame formed a dynamic product innovation design method spirally guided by double threads. An illustrative design case of the grain drying machine demonstrates that the proposed model is prone to successful development of creative products and consistent with the design cognitive model. This research can provide product evolutionary design some reference for further systematic and computerized.