The well designed for geothermal exploration and production in Daying， Yuanping was completed at depth of 3088m. To find out hydrogeological parameters and water recharge of 494~3088m formation， it was divided with four pumping test sections based on core and logging data； meanwhile， the target aquifer needed to be restored as much as possible after tests. According to the principle of “multi-level sealing in a single diameter hole”， a new water sealing process was designed with the water-stop tray for inside-pipe sealing and the canvas umbrella for outside-pipe sealing. This process simplifies the well structure and avoids clogging caused by dropping clay balls， injecting cement， etc. from outside the pipe. Field use shows that this process meets the water-sealing requirements of hydrogeological pumping tests， and can provide reference for similar projects.