The invention discloses a three-fluidized-bed solid heat carrier coal pyrolysis, gasification and combustion cascade utilization method. The method comprises the following steps of: mixing coal and high temperature circulating ash serving as a solid heat carrier in a fluidized bed pyrolysis furnace, pyrolyzing to separate out volatile, cooling and separating the volatile to obtain tar and pyrolysis gas, conveying pyrolysis semi-coke generated by pyrolyzing the coal to a fluidized bed gasification furnace, performing gasification reaction by using water vapor and O2 as gasification agents to prepare synthesis gas, conveying the semi-coke which is incompletely gasified in the gasification furnace to a circulating fluidized bed combustion furnace, blowing air for the conventional combustion or blowing O2/CO2 for oxygen-enriched combustion, heating the circulating ash serving as the solid heat carrier, and producing gasification agent vapor required by the gasification furnace by using high temperature flue gas generated by combustion. The method has the advantages that: the tar, the pyrolysis gas and the synthesis gas are co-produced through coal pyrolysis, gasification and combustion cascade utilization, the gasification condition of the semi-coke is reduced, and good economic benefits and social benefits are achieved.