The invention discloses a crowd counting method and a system based on a scale pyramid neural network, wherein the scale pyramid neural network structure is composed of VGG-16 as the basic skeleton, and multi-scale high-level features are extracted by embedding a scale pyramid module in the high-level. The scale pyramid module consists of four parallel cavities with different expansion ratios. Themethod comprises steps: inputting a picture to network, after a series of convolution, getting high-level features and transfering them to scale pyramid module, generating four kinds of feature maps,these four kinds of feature maps and the feature maps input to the module being in the 'channel' dimension series connection, transfering to the next convolution layer, and finally getting the densitymap through the convolution of 1*1. Compared with the prior art, the method of the invention has more efficient, more accurate and simpler network structure, and can apply modules for handling multi-scale problems to deep networks.