A new product conceptual design approach is put forward based on Hopfield neural networks models. By research on the mechanisms of Hopfield neural networks, the associative simulation approaches are proposed. The approach is given by Hebb learning law, Hopfield neural networks and crossover and mutation.The calculating models and the calculating formulas for the conceptual design are put forward. Finally, an example for the conceptual design of a solar energy lamp is given.The better results are obtained in the conceptual design. By research on the mechanisms of Hopfield neural networks, the associative simulation approaches are proposed. The approach is given by Hebb learning law, Hopfield neural networks and crossover and mutation. The calculating models and the calculating formulas for the conceptual design are forward. Finally, an example for the conceptual design of a solar energy lamp is given. The better results are obtained in the conceptual design.