The invention discloses a 17-Iodoandrosta-5,16-dien-3beta-ol preparation method. The 17-Iodoandrosta-5,16-dien-3beta-ol preparation method takes dehydroeopiandrosterone-17-hydrazone, trichloroisocyanuric acid (TCCA), tetramethyl guanidine (TMG) and elemental iodine as raw materials to react at 0-90 DEG C with existence of solvent and then performing treatment to obtain the 17-Iodoandrosta-5,16-dien-3beta-ol. According to the 17-Iodoandrosta-5,16-dien-3beta-ol preparation method, the TCCA serves as oxidizing agent, the elemental iodine serves as iodinating agent, an oxidizing iodination methodis applied to iodinating dehydroeopiandrosterone-17-hydrazone, so that, compared with traditional methods, the 17-Iodoandrosta-5,16-dien-3beta-ol preparation method can reduce consumption of the elemental iodine by a half and is simple in operation of reaction processes and easy to control, thereby having a good industrialized application prospect.