Abstract: The advanced secondary passive residual heat removal system (ASP) is one of several passive safety systems designed to ensure the safety of the reactor core. Test study on heat transfer capability of ASP was performed by using the high temperature and high pressure thermal-hydraulic test facility. In this paper, test facility was introduced, and the results of integral effect test and steady state test were discussed as well. The results show that stable natural circulation is built in the integral effect test, and heat transfer capability is verified as well in the long-time cooling period in station black-out (SBO) scenario. In the steady state test, the test facility can successfully remove the design heat from the core when ASP pressure equals to 8 MPa. Meanwhile, it is found that the heat transfer capability gets stronger with the increase of loop pressure.