This paper is concerned with the development of a novel sodium ion channel optical model by using the equivalent lens point spread function and the optical linear superposition principle. The main parameters and the corresponding equations of proposed model are studied and calculated. The relationship among the optical response index, membrane potential and time is investigated as well. Furthermore, performance evaluation by simulating and analyzing the membrane depolarization, the local potential and the dynamic spatiotemporal processes are undertaken to prove the correctness and effectiveness of the proposed model.