The invention relates to a method for preparing a hydrophobic coating through liquid material thermal spraying. The method includes the following steps that fusible polytetrafluoroethylene particles are added into a solvent, and turbid liquid is obtained; the surface of a matrix is subjected to pretreatment oil removal and roughening; and the turbid liquid is sprayed to the pretreated surface of the matrix through liquid material thermal spraying, and the hydrophobic coating is prepared. The liquid material thermal spraying is liquid material flame spraying or liquid material plasma spraying. The mass percent of the fusible polytetrafluoroethylene particles in the solvent ranges from 10% to 50%, and the particle size of the fusible polytetrafluoroethylene particles ranges from 10 micrometers to 100 micrometers. The method for preparing the hydrophobic coating has the advantages of being simple, low in cost, flexible in process, free of following processing and suitable for industrial production, achieving one-time forming and the like; and the method has wide application prospects and economic benefits in the field of coating preparation.