The invention relates to a simple preparation method of 4-chlorothiophenol. 4-chlorobenzenesulfonyl chloride is prepared from sodium 4-chlorobenzenesulfonate and thionyl chloride as raw materials andtoluene as a solvent through a reaction at 50-70 DEG C for 3-5 h under the action of a phase transfer catalyst and reduced by iron powder at the temperature of 40-60 DEG C under an acidic condition, and 4-chlorothiophenol is obtained. The method has the characteristics of being low in cost, simple and convenient to operate and suitable for industrial production.