Abstract: The regulation accuracy of the flow rate in the steam generator heat transfer of HTGR steam generator test loop must be very high, and whether electrical regulation valve can fulfill the requirement needs to be analyzed and verified. The drag coefficient and regulation accuracy of an electrical regulation valve were tested in an atmosphere pressure and temperature test loop. Then the regulation accuracy in the real working condition was analyzed. The regulation accuracy of a single valve is relatively low, and the flow rate variation with the minimum step size of the electrical regulation valve is 2.4%. Using two valves can increase the regulation accuracy. When the ratio of the drag coefficients of the fixed and working valve is 5∶1, the flow rate variation with the minimum step size is 0.175%. The regulation accuracy increases with the ratio.