The present disclosure belongs to field of nondestructive testing and positioning of urban water supply pipe leakage in municipal engineering and discloses a method for detecting leakage of water supply pipe based on ground-penetrating radar three-dimensional image attribute analysis including: acquiring ground-penetrating radar original image data of water supply pipe by longitudinal scanning; de-noising and filtering acquired original image data; fitting processed image data into three-dimensional data body by interpolation, extracting multiple planar or stereo image attributes and displaying image attributes by longitudinal, transverse, horizontal, irregular profiles and iso-surface; and accurately identifying and positioning pipe leakage positions and scale by multi-attribute comprehensive analysis. In this disclosure, leakage position is accurately positioned; spectrum with rich information is obtained based on extracted frequency attributes, leakage position is further verified; and high-resolution imaging is performed on leakage features based on extracted amplitude attributes, and the scale of pipe leakage is determined.