The invention discloses a preparation method for a microbial corrosion-resistant TiN/Ti ceramic metal composite coating. The preparation method comprises the following steps that 1, TiN particles areprepared by adopting a carbon thermal reduction method; 2, TC4 titanium alloy powder and the TiN particles are uniformly mixed to obtain spraying powder; and 3, the spraying powder is dried, and thenis sprayed on the surface of pipeline steel by adopting a plasma spraying process to obtain the microbial corrosion-resistant TiN/Ti ceramic metal composite coating. The ceramic metal composite coating prepared by using the preparation method has excellent microbial corrosion resistance, when the ceramic metal composite coating is used in a microbial corrosion working environment of the pipeline steel of a long conveying pipeline, the coating material shows excellent microbial corrosion resistance, and can meet the working environment requirements of the pipeline steel of the long conveying pipeline, so that the problem of microbial corrosion of the pipeline steel of the long conveying pipeline is effectively solved, and a good application prospect is achieved in the protection field of the long conveying pipeline.