To investigate the optimal pH value and reduction kinetics of sulfate reducing bacteria (SRB) under different carbon source conditions, sugarcane bagasse and sodium lactate were used as carbon sources to treat sulfate acid wastewater by SRB. The results showed that the sulfate removal rate of SRB was the best at pH 6 using sugarcane bagasse and sodium lactate as carbon sources, with a maximum removal rate of sulfate 71.82 % and 85.31 %, respectively and redox potential of the two systems -242 mV and -164 mV, respectively. At pH equals four, SRB with sugarcane bagasse as carbon source had better sulfate removal efficiency than that with sodium lactate, with the maximum sulfate removal rates of SRB 49.04 % and 36.24 %, respectively; and system REDOX potential -229 mV and -57 mV, respectively. The reduction process of sulfate radical by SRB conforms to the first-order kinetic model under both carbon sources. In the system with sugarcane bagasse as carbon source and pH equals 6, the maximum reduction rates of sulfate were 0.20007/d and 0.12688/d, respectively.