To study the cumulative effects of ecological water conveyance on groundwater in the lower Tarim River, a numerical model of local groundwater under the intermittent conveyance in a typical plain section of the lower Tarim River was established, taking the Alagansection and the 12th-18th ecological water conveyances as examples. Due to the lack of actual evapotranspiration data in this area, this study adopted the advectionaridity model based on the complementary relationship theory to calculate the actual monthly maximum evapotranspiration rates. After the calibration and verification, this model can be applied to evaluate the cumulative effect of ecological water conveyances on the groundwater. It is an effective method to describe the spatial and temporal response of groundwater to the ecological water conveyance. The spatiotemporal distribution pattern of groundwater before and after the water conveyance is revealed by two indicators, the effective response distances of groundwater to water conveyance and the response areas. The results showed that the maximum response distance from the groundwater to the channel was extended from 812m to 1100m. The response areas of middle and high level were 1.61 times of that of low water level. The effective range of water conveyance was mainly distributed within the range of 1000~2000m from the channel.