Based on the panel vector autoregression (PVAR) model, the panel data of 18 provinces (municipalities and autonomous regions) in the Yangtze River and Yellow River basins from 2011 to 2020 were collected in this paper. On the basis of verifying the validity of the panel data, the results of the model were analyzed, the impulse response plot function and the variance decomposition results were analyzed, and the interaction and dynamic two-way impact between reclaimed water input and the economic development of the Yangtze River and Yellow River basins were investigated. The findings reveal that there is a mutually reinforcing and co-developing relationship between the reclaimed water input and the economic development of the basins, which exhibits regional disparities. In terms of the impact of the river basins’ economic development on the reclaimed water input, the Yellow River Basin demonstrates significantly greater dependence than the Yangtze River Basin. Concerning the economic development of the basins, the introduction of reclaimed water input exhibits positive effects in both the Yellow River Basin and the Yangtze River Basin. However, the lag of the positive impact in the Yangtze River Basin is more significant.