介绍在炼钢厂连铸连轧生产线上对热轧方形钢坯实施计算机控制喷号的必要性，计算机控制热轧钢坯喷号机的结构原理及控制系统。喷号机在计算机的控制下，自动完成定位、喷号、清洁喷头等工作。研究、开发用水基耐高温涂料作为喷号材料，字迹清晰，附着牢固，效果很好，为进一步推广应用创造了条件。 This paper introduces the necessity of implementing computer controlled spray numbering of hot-rolled square billet in the continuous casting and rolling production line of steelmaking plant, and the structural principle and control system of computer controlled hot-rolling billet squirting machine. Pen machine in the computer’s control, automatic positioning, Pen, cleaning nozzle and other work. Research, development of high temperature water-based paint as a spray material, clear writing, solid adhesion, the effect is very good, to further promote the use of applications to create the conditions.