《钢结构设计标准》（GB 50017—2017）中的单轴对称工字形截面钢梁弹性整体稳定系数是计算钢梁整体稳定承载力的重要系数，但其中的系数是经过一些列简化得到的，不符合当前精细化计算的要求。提出求和形式的翘曲惯性矩的精确计算式，给出其他几何参数的求和形式的精确计算式；基于边缘纤维屈服准则，以钢梁弯扭屈曲临界弯矩的通式及弹性极限弯矩为基础，提出梁的整体稳定系数定义式，推导了单轴对称工字形截面钢梁弹性整体稳定系数的精确算式。基于弹性整体稳定系数的精确算式和求和形式的几何参数精确计算式，揭示《钢结构设计标准》（GB 50017—2017）中的等截面焊接工字形和轧制H型钢简支梁的整体稳定系数存在的问题；采用现有文献中的数据，验证弹性整体稳定系数的精确算式的适用范围和计算精度。结果表明：《钢结构设计标准》（GB 50017—2017）中稳定系数的主要问题为：几何参数计算式的过度简化，等效弯矩系数的适用范围有限，钢号修正系数的计算方法有误；而单轴对称工字形截面钢梁弹性整体稳定系数的精确算式，不但适用范围广，而且计算精度非常高。

The elastic overall stability factor of singly symmetric I-section steel beams in Standard for Design of Steel Structures(GB 50017—2017) is an important factor for calculating the overall stability bearing capacity of steel beams, but the factor is obtained through a series of simplifications, which does not meet the current requirements for refined calculation. Formula for warped moment of inertia in summation form was proposed and other geometric parameters in summation form were then given. Based on the first yield moment criterion, formula for elastic overall stability factor was defined by employing general expression of critical moment and elastic ultimate moment, and precise formula of elastic overall stability factor of steel beams with singly symmetric I-section was derived. The problems in Standard for Design of Steel Structures (GB 50017—2017) were revealed on the basis of the precise formula of elastic overall stability factor and geometric parameters in summation form. Comparisons were made for verifying the correctness of the precise formula of elastic overall stability factor by employing the results in literatures. The results show that the problems of overall stability factor in Standard for Design of Steel Structures(GB 50017—2017), are oversimplification of formula of geometric parameters, limited application range of equivalent moment factor, and the wrong expression of steel grade correction factor. The precise formula for the overall elastic stability coefficient of a single axis symmetrical I-shaped section steel beam is not only widely applicable, but also has very high calculation accuracy.