Abstract: In order to reduce the fly ash fusion temperature in the Huainan coal gasification process and solve the application of high ash fusion temperature coal to the liquid slag discharging gasifier, the blending experiment design was applied to the optimization on No.1 coal gasification complex flux (calcium-base flux) , No.2 C oal gasification complex flux (magnesium-base flux) and No.3 coal gasification complex flux (iron-base flux) .With the fly ash flow temperature as the evaluation index, t he optimum complex conditions were optimized for the selected flux and the mathematics regression model was established.The results showed that the predicted valu e of the fly ash flow temperature obtained from the regression model would have a difference within 20。C to the experiment measured value.With the blending experime nt design, when the quality fractions of the three fluxes were individually as 0, 0.47 and 0.53, those fluxes would have the best fusion assistance effect to the selected C oal samples and the predicted results of the mathematics regression model would be the same to the experiment results.