The structure of spiking neural network (SNN) is presented,which is regarded as the third generation of artificial neural networks (ANNs) and established based on the simulation of network model for biological visual cortex. The conductance based on integrate-and-fire spiking neuron model is given,and then the neural network is applied to edge detection of leucocythemia marrow images. The experimental results show that SNN can be applied in leucocythemia marrow image segmentation. The lower the firing threshold is,the more details will be displayed.