Abstract: Karez is a great ancient water conservancy project, which is still playing an irreplaceable role in local irrigation, drinking water, and environmental protection in Turpan. Due to artesian water all year around, apart from meeting a few needs of domestic-water use in non-irrigation periods, most of the water evaporates, leading to water waste. Based on the analysis of geological conditions and the unique operating mechanism of Turpan’s Karez, in this paper, radiation tube was proposed to increase and control water. The main idea of this technique is to reinforce the Karez catchment segments and set up horizontal radiation tubes in the head of the catchment; it means changing the original Karez sidewall catchment into radiation tube catchment. The radiation tube outlet must be connected to the main water pipe, setting the control valve to control the amount of water flow artificially. A numerical simulation method was used to investigate how the radiation tube affected the groundwater of local area, how much water increased, how tubes were reasonablly settled in order to demonstrate the feasibility of the technique. A Karez’s radiation tube system seepage field model was established by using a three-dimensional modeling method to calculate the seepage field. The model parameters were from actual working conditions. The results showed that: 1) Total head contour changed from high to low from upstream to downstream strata, and the total head contour of the central part of the downstream strata being lower than the left and right, resulting in the water catchment capacity of Karez; At the same time, there was a significant reduction in total head contour in the same position after addition of radiation tubes, indicating that adding radiation tubes can lower the groundwater level; 2）Compared with the calculation results of no radiation tubes, radiation tubes could reduce the seepage line significantly; After addition of radiation tubes, water catchment capability greatly increased in the Karez-Radiation tube system; Under normal effluent conditions, seepage line were lowered to the top of the Karez, the range also was expanded a lot, which means that the effect of radiation tubes is obvious; 3) Scope of catchment would be expanded and water flow could reach more than double after the transformation of the Karez by utilizing the radiation well; The water scope of the Karez system after transformation increased to 1644-3967 m3/d; 4) After closing the valve when the water was full in the compartment of the water main, the total head contour changed smoothly. This explained that when the valve was closed, groundwater did not flow from the main pipe, radiation tubes stopped from collecting water. Thus, the setting of a control valve can overcome the deficiencies that the amount of Karez water cannot control. It is a very precious and effective method of protecting groundwater resources in the Turpan region.