The evaluation index system of water resources carrying capacity was proposed based on four systems including water resources system, social system, economic system and ecological environment system. Taking the macro behavior of the system as the research object, the evaluation model of water resources carrying capacity based on system coordination was constructed by introducing the order parameters that affected the evolution process of the system. The model was validated by taking the assessment of water resources carrying capacity of Guangzhou in 2019 as an example. The results show that Conghua District, Central District and Panyu District are in the level of water resources overload. Huangpu District and Nansha District have better water resources carrying capacity. Huadu District and Zengcheng District are facing the problem of water resources shortage in varying degrees, and there is the risk of water resources overload. The evaluation results are in line with the actual situation of Guangzhou City, and verify the effectiveness and applicability of the model, which can provide reference for regional water resources planning and management.