The invention provides a method for upgrading coal pyrolysis, comprising the following steps: (a) sending raw coal with granularity being less than and equal to 30mm into a rotary drier, so that the raw coal and hot flue gas are connected with each other by the means of parallel flow and directly change heat, and the raw coal exchanges heat indirectly with hot semicoke from a pyrolyzer in the rotary drier, to dry the raw coal; (b) mixing the dried raw coal with the high-temperature semicoke from a heating rotary kiln and sending the mixture into the pyrolyzer, wherein the coal material directly changes heat with the high-temperature semicoke and pyrolyzes to generate hot semicoke, tar steam and coal gas, wherein final pyrolyzing temperature is 500 DEG C-700 DEG C; and (c) sending a part of the hot semicoke generated into the heating rotary kiln for processing by means of heating, and sending the rest part of the hot semicoke into the rotary drier for exchanging heat directly with the raw coal. The method for upgrading coal pyrolysis has flexible operation, wide granularity range of the coal material, good quality of the generated semicoke and the generated tar, high cascade utilization of energy and high system thermal efficiency, properly solving the technical problems such as dust and tar blocking, high dust content in the tar, etc.