The low cost preparation of TiAl master alloy is an important direction of current research. In this paper, TiO2 as raw material, KClO3 as heating agent, Al as reducing agent and alloying agent, Ca as deep reducing agent were used for the preparation of TiAl master alloy by metallothermic reduction method. The heat effect per unit mass, the proportion of slag-making agent, the amount and composition of reducing agent on the stability of the reaction process, the composition and yield of alloy were investigated. The results showed that when Ca and Al were used as reducing agents, the adiabatic temperature of the system was 2426 K and 1806 K, respectively. The TiAl master alloy was composed of TiAl, Ti3Al and a small amount of Al2O3 inclusions. The contents of Ti, Al and O in the alloy were 58.36%, 40.19% and 1.41%, respectively.