Abstract: Cylindrical latticed sheel structures are widely used in indoor coal storage yard of the power palnt.However,due to the rusty atmosphere and the gravity of the coal,the rusty and bending bars appeared in the use of the structures.If there are too many members have seriously rusted and bent,the safety of the structures will be greatly decreased and even be collapsed.Taking the example of a practical engineering,this paper studied the influence of imperfection to the strength and stability of structures and established a model for calculating the corrosion and bending of members.In the final,the paper introduced the method of calculating the bearing capacity of this kind of structures with a random imperfection model.