The invention relates to a preparation method of mesophase carbon microspheres and mesophase asphalt. The preparation method comprises the following steps: mixing coal-based asphalt with a first solvent to obtain a co-carbonized raw material; performing a first thermal polycondensation reaction on the co-carbonized raw material to obtain polycondensed asphalt containing the mesophase carbon microspheres; mixing the polycondensed asphalt with a second solvent, dissolving, separating to obtain a solid component and a liquid component, drying the solid component to obtain the mesophase carbon microspheres, and distilling the liquid component to obtain a byproduct asphalt; performing a second thermal polycondensation reaction on the byproduct asphalt to obtain the mesophase asphalt, wherein the coal-based asphalt comprises coal tar asphalt and/or residue-refined asphalt; the first solvent is distillate with the temperature being lower than or equal to 400 DEG C, which is obtained from coaltar cutting. By the preparation method provided by the invention, two high-added value products of the mesophase carbon microspheres and the mesophase asphalt can be obtained at the same time, and the problem of a single product structure of an enterprise is solved.