Abstract: A power plant has optimized the operation mode of the desulfurization system through repeated tests to solve the problems of diverse and complex types of coal combustion, high sulfur content of coal blending and insufficient quality and activity of limestone powder. It controls the slurry pH value, limestone slurry density and slurry density of the absorption tower. On the basis of ensuring the normal environmental protection parameters, it reduces the unit consumption of limestone powder, saves limestone powder and reduces the desulfurization operation cost.