One of the basic goals of modern neuroscience is to study the brain-wide complex neural network of mammals' brain. Because of the technological limitations, the traditional tools can only study the local circuits of the higher animals or the small brain network of the lower animals. Here we review recent efforts to resolve the contradiction between large specimen and high-resolution, and some of them have been applied to image the neural network in mammals' whole brain. We focus on some technology index includes spatial resolution, detection range, data registration and throughput, and also discuss the challenges of the emerging methods.