Rodent animals can solve the space problem by means of forming a cognitive map in the hippocampus representing the environment. In the classic model of cognitive map,the system needs large amount of physical exploration to study the spatial environment so as to solve path-finding problems,which costs a lot of time and energy. Although the Hopfield’s mental exploration model makes up the deficiency mentioned above,the efficiency of the path has not been focused in the model. Moreover,this model mainly comes from the artificial neural network,lacking of clear physiological significance. In the paper,based on the concept of mental exploration,the neural energy coding theory was applied to the calculation model so as to solve the path search problem: an energy field was constructed in the model on the basis of the firing power of position cell clusters,and the energy field gradient was calculated which can be used to study the mental exploration problem. The study shows that the new mental exploration model proposed can efficiently find the optimal path,and present the learning process with biophysical meaning as well. The new idea verifies the importance of position cell and synapse on the spatial memory and the efficiency of energy coding,which provides the theoretical basis for the neural dynamics mechanism of spatial memory.