Experimental system of a new entrained flow gasifier with second-stage water supply (20 kg/h) was set up in this paper, and effect of molar ratio of O/C on temperature distribution, syngas composition, carbon conversion and effective syngas were analyzed with a typical high AFT coal (Guizhou LJ coal). The results of non-second stage water and second-stage water with changing molar ratio of O/C indicate that, when the molar ratio of O/C is larger than 0.96, gasification efficiency with dry slag by second-stage water would become better than non-second-stage water. Specifically, when the molar ratio of O/C was 1.1, the effective syngas fraction and carbon conversion of second-stage water gasification were 80.2% and 93.24% respectively. Correspondingly, the effective syngas fraction and carbon conversion of non-second-stage water gasification were 78.5% and. 91.67% respectively. Furthermore, the gasification temperature was lower than the ash fusion temperature of test sample, the slag was non-melt during all the gasification experiments. The optimal gasification was conducted with the process temperature under 1450 degrees C, which was lower than the ash fusion temperature of gcoal. These experimental results prove the applicability of entrained flow gasification technology with dry slag by second-stage water supply on using high AFT coals, which is helpful to generalize the large-scale gasification technology using abundant high AFT coals in China. (C) 2016 Elsevier B.V. All rights reserved.