Compared with the traditional artificial neural network, pulse neural network has the advantages of hardware-friendliness and low energy consumption. Compared with the electric pulse neural network, the photon pulse neural network has the advantages of high speed, low energy consumption, large transmission capacity and strong anti-electromagnetic interference ability. Based on the semiconductor optical amplifier (SOA), a new neuron model of photon pulse—LIF (leakage integration and fire) model is designed in this paper, and the application of LIF model in digital logic is explored. The “XOR” logic function based on the model is realized, and an excitatory and inhibitory neuron is improved, LIF model, XOR logic and good output of excitatory and inhibitory neurons were obtained by optical communication simulation software.