The invention relates to the technical field of combustion and provides a combustion-supporting alloy. Materials for preparing the combustion-supporting alloy include, by weight, 60-80 parts of tungsten, 40-60 parts of a hafnium alloy and 20-30 parts of rhenium. The combustion-supporting alloy can resist high temperature. The invention further provides a water steam combustion participating method. The steam combustion participating method comprises the following steps that carbon containing fuel with carbon being a principal component is conveyed into a boiler, the carbon containing fuel is combusted under the action of a combustion-supporting alloy body which is arranged in the boiler, when the temperature of the combustion-supporting alloy is raised to 1,500 DEG C or above, water steam is introduced into the boiler, and the temperature of the water steam ranges from 100 DEG C to 500 DEG C, wherein the combustion-supporting alloy body is prepared from the combustion-supporting alloy and is internally provided with a plurality of holes for the water steam to pass through, and the method can prevent the phenomenon that the holes of the combustion-supporting alloy are blocked as the temperature is too high. The invention further provides a boiler combustion system for implementation of the method. The boiler combustion system can prevent hole blockage caused by the too high temperature of the combustion-supporting alloy.