The invention provides a preparation method for controllable hollow mesoporous silicon dioxide nanospheres. The method comprises the following steps of: dissolving iron salt, acetic acid and polyvinylpyrrolidone in ethanol, and uniformly stirring and mixing, then transferring the solution into a polytetrafluoroethylene reaction kettle, and reacting while heating to obtain an iron oxide nanoparticle suspension; adding ethanol, deionized water and cetyl trimethyl ammonium bromide into the iron oxide nanoparticle suspension, adding alkali to adjust the pH value to be 7-12, slowly adding tetraethoxysilane in a stirring condition so as to for 12-72 hours, filtering, drying, and roasting at 400-600 DEG C, thus obtaining a mesoporous silicon dioxide-coated iron oxide nanomaterial with a core-shell structure; and completely soaking the obtained mesoporous silicon dioxide-coated iron oxide nanomaterial with the core-shell structure in a prepared acidic etching solution, dissolving an iron oxide used as a hard template, and washing with the deionized water and the ethanol, filtering and drying, thus obtaining the hollow mesoporous silicon dioxide nanospheres. The preparation method for the controllable hollow mesoporous silicon dioxide nanospheres disclosed by the invention has the advantages of being simple in synthesis process, moderate in operation condition, cheap in raw material and easy in acquisition of raw materials, and easy in enlargement and synthesis.