The proper amount of silica in the raw material of the sinter production contributes to the formation of the sintered binding phase, but the high silica content increases the liquid phase viscosity and adversely affects the mineral composition of the sintered binding phase. The influence of high-silica iron ore from Brazil on the sintered binding phase is still unclear. Therefore, the micro-sintering method was used to investigate the liquid phase fluidity of the mixed ore in different proportions of the high-silica ore powder. Based on the principle of "K-value method", the semi-quantitative analysis of its minerals was carried out to obtain the content of minerals such as fayalite, calcium fayalite and calcium silicate. The results showed that with the increase of the ratio of the high-silica iron ore powder in the mixed ore, the liquid phase fluidity of the binding phase decreased, and the mineral contents such as fayalite and calcium silicate also increased significantly. Based on this, the method of improving the reactivity of the mixed ore was used to improve the liquid phase fluidity of the sintered binding phase and reduce the content of fayalite and calcium silicate.