The carrying capacity of water resources in the Heilongjiang River Basin affects the natural ecological environment of China and Russia, and is of great importance for the conservation and effective use of water resources in both countries. By analyzing the water supply and produced water footprints of nine related political regions in the Heilongjiang River basin, the RG-RP relationship diagram method was used to compare and analyze the water resources carrying capacity of the related political regions in the basin. The results show that: Heilongjiang Province has the strongest water supply capacity among the four political regions in China, and Khabarovsk Territory has the strongest water supply capacity among the five political regions on the Russian side; China has a significantly larger produced water footprint and higher water stress than the Russian side, with Liaoning Province being the most significant. It is concluded that the water use efficiency of Chinese political regions is higher, the degree of water resources exploitation is lower, and the water resources carrying capacity is better than the Russian side. It provides a reference for water resources monitoring and environmental protection in the cross-border watersheds of China and Russia.