In order to reasonably synthesize the carrying capacity of regional water resources by the four elements of water quantity, water quality, water space and stream flow, a water resources carrying capacity evaluation model based on the four elements and a risk matrix(QQSS-RM)was proposed. Firstly, 48 preliminary evaluation indicators under the subsystem of quantity-quality-space-stream were constructed and the weight of each evaluation index in the four elements was calculated by expert consultation information method and genetic analytic hierarchy process. Through screening and analysis, 8 comprehensive evaluation indexes were obtained to construct the evaluation index system for the regional water resources carrying capacity. Secondly, 4 evaluation grade criteria of 8 comprehensive evaluation indexes were obtained by referring to relevant literature and expert opinions. Finally, an evaluation model of water resources carrying capacity based on QQSS-RM was constructed, which was applied to three third grade zones of water resources in the Xiliao River Basin. The results show that the water resources carrying capacity evaluation level of Xilamulun River and Laoha River, Wulijimulun River and the downstream of Xiliao River are overloaded, critical overloaded and overloaded respectively, showing a poor water resources carrying capacity of the Xiliao River Basin. The evaluation results are basically consistent with the current status of the Xiliao River Basin, indicating that the QQSS-RM model has better application value in regional water resources carrying capacity evaluation.