Minimizing of heat loss of liquid steel through the ladle lining led to the integration of increasing insulation function of the permanent lining and high-quality insulating layer between the permanent lining and the ladle steel shell. In this paper, a study was made on physical and thermomechanical properties and corrosion resistance of calcium hexaluminate based castables. The chemical and physical properties of CA6 based castables fabricated in this work can fulfill general requirements of the permanent lining in ladle. The permanent linings of CA6 based castables offer superb thermal insulation and corrosion resistance, compared to conventional refractory systems of 300t ladle in Baosteel. Both functions of insulation and safety work effectively in whole process of ladle operation.