Abstract: The paper introduced composition of a water flow calibration facility which uses weighing method to calibrate standard meters and standard meter method to calibrate measured meters and expounded hardware composition, working principle and design scheme of human-machine interface of control system of the facility. The control system uses S7-300 PLC to collect and process data of the facility and control water-pumps and direction changer, and uses SIMATIC WinCC to realize functions of display of water flow calibration result, parameter setting, form generation, form storage and form inquiry. The testing result showed that both linelikeness and repeatability of vortex flow meter calibrated by the facility achieve precision of 1.0 level and the control system is stable and reliable with little uncertainty.