Studied are the ash fusion characteristics obtained from the mixed incineration of 1. three types of coal (Yuanbaoshan-origin lignite, Cuijiagou-origin bituminous coal and Xuzhou bituminous coal, hereinafter referred to as coal Y, coal C and coal X for short respectively), which have different ash fusion characteristics, and 2. chemical waste-liquid red water with different salt contents (the content of alkali metal sodium salt Na2SO4, NaNO3 and Na2CO3 etc. in red water, hereinafter generally referred to as the salt content) . The study results show that if no limestone is added, the ash fusion temperature of coal X and coal C tends to go down as a result of an increase in salt content of the red water, during which under an identical salt content, the ash fusion temperature of coal X drops by a relatively big margin and that of coal Y tends to go down at the beginning and then go up followed by a go-down. After limestone (Ca/S = 2.0) has been added, with an increase in the salt content of the red water, the ash fusion temperature of coal X displays a tendency to first fall and then rise and there exists a minimum value among its four characteristic temperatures when the salt content of the red water is 10%. By contrast, the ash fusion temperatures of coal C and coal Y undergo a change similar to the case when no limestone is added. However, the above change is relatively small. At a certain salt content (15%) and with an increase in added amount of limestone, the ash fusion temperature of coal X and coal C will all first go down and then up, but for coal X there is a significant change. The deformation and softening temperature of coal Y rises while its hemispheric and flow temperature goes down first and then up. The research results provide a theoretical basis for the prevention of coking of bed materials when organic salty waste liquid is fired in a fluidized bed.