During the fixed bed tube fuace combustion experimental study, stimulated the calcium-based sorbent grain size and microstructured influencing factors to explain the fluorine retention effect influence law, and expounded the combustion fluorine retention agent developing principle, and probed into the high-temperature fluorine retention agent technical approach. The results show that the calcium-based sorbent particle grain size and pore structure also have the bigger influence on the combustion fluorine retention ef-fect, and reducing the calcium-based sorbent particle grain size and improving the calcium sorbent structure characteristics at very high temperature to enhance the fluorine retention effect is the important approach to the fluorine retention agent development.