The invention discloses a preparation method of a shape-controllable hollow carbon microsphere, belonging to the technical field of energy materials. The preparation method comprises the following steps of: firstly, preparing a polystyrene microsphere with monodispersity by adopting a soap-free emulsion polymerization method; modifying the surface of the polystyrene microsphere by acidizing treatment of concentrated sulfuric acid to enable the surface to have a sulfonic acid group (-SO3H-) with initiation activity to resol; then, dropping a resol ethanol solution into anhydrous ethanol in which the modified polystyrene microsphere is dispersed to enable the solution to carry out cross-linking reaction on the surface of the microsphere to prepare a compound microsphere in a core-shell structure; and finally, putting the compound microsphere in the inert gas protecting environment for carbonizing. The invention can effectively control the particle size of the hollow microsphere by changing the particle size of the microsphere, avoids an operating process of removing a template, effectively reduces the preparation processes, and can realize the purpose of controlling the shape of the hollow carbon microsphere only by changing one variable in the same system.