Aiming at the problem of water resources shortage in China, the evaluation index system of regional water resources carrying capacity was constructed in the four dimensions of water resources, virtual water, ecological environment and social economy, in which the new concepts and characteristics of virtual water were combined. Variable weight method was used to determine the weight of evaluation index. The improved matter-element extension model of water resources carrying capacity under the influence of virtual water was constructed and applied to 9 cities in Guangdong-Hong Kong-Macao Greater Bay Area. The results show that the water resources are overloaded in Shenzhen, critically overloaded in Guangzhou and Foshan, and weakly bearable or bearable in other cities. The model evaluation results can provide reference for regional water resources optimal allocation. Keywords: virtual water;water resources carrying capacity;improved matter-element extension model; variable weight method 〖FL