To study the explosive spalling and compressive strength degradation of reactive powder concrete (RPC) after high temperature treatment, the high temperature test and compression test were carried out by 300 cube specimens with the size of 70.7 mm×70.7 mm×70.7 mm and 120 prism specimens with the size of 40 mm×40 mm×160 mm. The effects of fiber type, fiber content, heating temperature and specimen size on the compressive strength and failure characteristic of RPC were analyzed. The results indicate that the steel fiber volume dosage of 2% or polypropylene fiber volume dosage of 0.3% can effectively prevent RPC from spalling. The presence of steel fiber has active effect on the compressive strength of RPC after high temperature, and polypropylene fiber has adverse effect on the compressive strength. The compressive strength of RPC after high temperature increases first and then decreases with the increasing of temperatures. By regression analysis, the equations to express the relationship between compressive strength of RPC and exposure temperatures are proposed.