Abstract: The traditional capping technology exists the problems of the poor quality of trail billet, the low qualification rate of flaw detection and the long resection length in slab continuous casting. In order to solve the above problem, an anhydrous capping technology was developed and had been applied in a medium and heavy plate company by use of process innovation. “Watering” was changed into anhydrous in casting capping stage. The results showed that, the quality of trail billet was improved，the qualification rate of flaw detection increased from 78.2 % to 98.8 %, and the resection length reduced from 1.5-2.0 m to 0.8 m.

Key words: slab, anhydrous capping process, trail billet