Comprehensive understanding of heat transfer and erosion characteristics is of significance for circulating fluidized bed (CFB) optimization In this work, a high-fidelity simulation of the full-loop CFB is conducted using the CFD-DEM method After qualitative and quantitative model validations, the impact of superficial gas velocity on flow dynamics, particle temperature evolution, and cyclone erosion is comprehensively explored The results show that increasing superficial gas velocity decreases solid holdup and improves flow uniformity Probability density of particle temperature in different CFB components shows distinctive distributions The average particle temperature augments as the superficial gas velocity augments in fast fluidization regime, while it shows the opposite tendency in dilute phase transport regime Meanwhile, the cyclone erosion region gradually concentrates in the intersection of cylinder and cone parts The results benefit for in-depth understanding of heat transfer and erosion characteristics in CFB apparatuses.