As an important ecosystem service, surface water resource provisioning plays a key role in socio-economic development. Quantifying its supply-demand relationship and identifying the critical, imbalance areas can provide specific information for basin water resources management. Here, the Daqing River Basin, an area with severe water resource shortage, was taken as a case study region. The spatial flow of surface water resource provisioning service (SWRPS) and water resource demand were quantified by using InVEST model and statistics data, respectively. Then the supply-demand relationships of surface water resource provisioning service were assessed in terms of two policy scenarios (water resource utilization efficiency improvement and water-saving irrigation implementation). Compared with the upstream areas, the downstream areas of Daqing River Basin presented higher supply and demand of SWRPS. Agriculture was the main industry of water resource utilization. During 2010-2015, SWRPS increased by 0.97% while the water resource demand decreased by 9.6%. Consequently, the supply-demand ratio of SWRPS increased from 0.78 to 0.88. Although the spatial flow of SWRPS from upstream area mitigated the water resource pressure in the middle and downstream regions, the demand was still larger than the supply in SWRPS in the middle and downstream regions. However, improving water resource utilization efficiency and implementing water-saving irrigation would effectively improve the supply-demand relationships of SWRPS in Daqing River Basin, which could increase the supply-demand ratio to 0.97 and 0.96, respectively. The study provides an approach for quantifying the supply-demand relationship of SWRPS and identifying the potential of water-saving policies in water-shortage basin, which can also provide quantitative information for basin water resource management.