The utility model discloses a variable flow velocity water fetching system which comprises a water supply pipeline, a speed change device arranged at the tail end of the water supply pipeline, a POS and an IC card matched with the POS. A downward vertical water discharging pipe is connected to the tail end of the water supply pipeline, an adjustment pipe is connected to the outer wall of the water discharging pipe in a sliding and sleeved mode, the pipe edge at the bottom end of the water discharging pipe protrudes outwards and abuts against the inner wall of the adjustment pipe, and the pipe edge at the top end of the adjustment pipe protrudes inwards and abuts against the outer wall of the water discharging pipe; the speed change device comprises a heat insulation box arranged on the water supply pipeline, a master controller arranged in the heat insulation box, a sonic sensor arranged at the tail end of the adjustment pipe and connected with the input end of the master controller, and a ball valve arranged in the water discharging pipe and connected with the output end o the master controller. The POS is connected to the master controller. The variable flow velocity water fetching system can adjust the height of the water outlet to be adaptive to water fetching containers of different heights, the water velocity in the water fetching process can be controlled from high to low, water is stopped automatically until the water fetching container is full, and the variable flow velocity water fetching system is particularly suitable for boiling water rooms.