An innovative approach for quantitatively evaluating the Taihu Lake stone rockery characteristics was created in this research. Key features of the digital model, including model skeleton extraction, contour scatter extraction, geometric holes, and texture roughnes, were examined. High-precision surrounding rockery point cloud data were collected using laser scanning. Based on the traditional Chinese evaluation criteria for garden rockeries, “Shou (slim), Tou (riddled through), Lou (well hollowed out), and Zhou (wrinkled)”, a quantitative evaluation system with 14 indicators, such as body proportion, air permeability, and penetration rate, was proposed. It was determined through the case study of rockery in Shanghai and Yangzhou that the characteristics of “Lou (well hollowed out)” can be seen in the mutual weighting of leakage ratio, porosity, tangent ratio, and hole center distribution coefficient;; the air permeability, the hole rate, the hole penetration rate, and the hole center distribution coefficient can represent the characteristic of “Tou” (riddled through); “Zhou (wrinkled)” can be seen in the two indicators of roughness and roughness ratio; the body proportion, inflection number, contour curvature, and skeleton complexity can fully reflect the characteristic of “Shou” (slim). This method effectively makes use of the high-precision and multi-detail characteristics of laser point clouds. It also combines mathematical analysis and computer visualization. The quantitative evaluation approach can provide a scientific basis and new visions for the conservation and transmission of garden rockery heritage.