The invention relates to a preparation method of phenyl chlorosilane. The preparation method comprises the following steps: adding phenyl disilane and a catalyst into a reactor, uniformly mixing, then inhaling inert gas into the reactor and exhausting air, stirring, heating, continuously inhaling pyrolysis gas for reaction under a normal pressure condition, stopping the reaction, rectifying and separating the reaction liquid to prepare different types of phenyl chlorosilane monomers. The target products prepared by the method disclosed by the invention are various types of phenyl chlorosilane monomers; the method can be used for simultaneously preparing various types of high value-added phenyl chlorosilane such as methyl phenyl dichloromethylsilane, dimethyl phenyl chlorosilane, methyl diphenyl chlorosilane and the like; moreover, the yield is high, the yield of byproduct methyl chlorosilane is low, and high-value utilization of a silicon resource is realized.