The invention discloses a target detection method and system based on multi-scale feature fusion in an image. The method comprises the steps that firstly, zooming of different scales is carried out byutilizing the to-be-detected picture, and an image pyramid is constructed; secondly, a set of multi-scale detection templates covering most of the sample dimensions is obtained by utilizing a statistical clustering method; thirdly, based on the multi-scale detection template, scale self-adaptive target context construction is performed; fourthly, multi-scale depth features are fused; fifthly, thenon-maximum value restrain based on soft judgment is carried out. The invention is advantageous in that the image multi-resolution sparse pyramid, the multi-scale detection template and the templatescale self-adaptive context, multi-scale depth feature fusion and the like are constructed, full mining and fusion utilization of the depth features are achieved, and the target detection performancecan be improved.