Effects of three anti-explosion agents: fiber, azo amide, and metal aluminum powder, on the anti-explosion property of Al2O3-SiC-C low-cement castables were researched. The mechanism of the anti-explosion agents was studied by observing the microstructure of the castables. The results show that all these agents can improve the anti-explosion performance of the low-cement castables. The anti-explosion performance of the castables is the best by composite adding 0.12% fiber, 0.05% azo amide, and 0.1% metal aluminum powder. The main anti-explosion mechanism is that these three agents form apparent pores which increase the permeability.