Taken a rail car carrier project as an example, the design and layout optimization of drencher system in rail car hold are performed in section, pump set, intelligent remote control, nozzle layout, section line pipe layout, and so on. Compared with the basic design and layout, the optimization scheme is of the advantages of eliminating the blind spray areas in adjacent sections, reducing the pump set number, reducing the pipe material consumption, and reducing the site construction amount. After the actual ship tests, the design and layout optimization can provide valuable reference and lessons for the construction of drencher system in rail car hold of follow-up or similar ship type.