The finite element analysis method is applied to study the relationships between the gibbsite crystal overlapped angle and the strength of gibbsite particles.The regularity of the particle size of gibbsite with the strength is calculated.The results show that:(1)The strength of gibbsite is weak when overlapped angle of the crystals is between 60o~80o;(2)When the gibbsite crystals are smaller(about 5 μm),the gibbsite strength becomes better;(3)When the gibbsite crystals are larger(20~40 μm),the gibbsite strength is weaker;(4)The strength of gibbsite particle with different crystal sizes has obvious advantages.