The invention discloses a preparation method and an application of a high-dispersion anti-sintering supported type ruthenium catalyst. The catalyst is prepared through the process that volatile ruthenium species formed by heating ruthenium-containing precursors are deposited on a carrier material heated to a certain temperature. The preparation method comprises following steps: (1), the ruthenium-containing precursors with certain mass are heated to 450-1200 DEG C, and the volatile ruthenium species are formed; (2), carrier gas is introduced or the system is vacuumized, the volatile rutheniumspecies are migrated to the carrier material preheated to 450-1200 DEG C and are adsorbed and precipitated for a period of time, then heating for the ruthenium-containing precursors and the carrier isstopped, and after cooling, the high-dispersion anti-sintering supported type ruthenium catalyst is obtained. The mass fraction of ruthenium is 0.01%-10%, and average size of ruthenium nanoparticlesis adjustable in a range of 1-10 nm. The high-dispersion ruthenium catalyst with the average size being 1.1 nm has good activity and stability for a dry reforming reaction of methane and carbon dioxide, conversion rate of methane and carbon dioxide is higher than 97%, and activity keeps stable after the reaction is performed for 500 h at the temperature of 850 DEG C.