Abstract: The theoretical analysis on bending strain distribution around the cross-section circumference of a cylindrical alignment cell specimen with multiple-point measuring way was made. The general equation for calculating maximum bending strain had been developed to theoretically unify the expression of loading coaxality. Also both the equation for angle position of maximum bending strain and the equation for net bending contributions respectively due to the testing machine and the specimen was provided. The error in reference <参考文献原文>in regard to represent the net bending strain component due to testing machine was pointed.