本文采用截面应力分析的方法从实心圆截面扭转入手,推导出实心圆截面最大切应力计算公式,与目前使用的公式一致。将这一方法运用到矩形,得到正方形截面扭转最大切应力计算公式,并与目前采用的经验公式进行比对计算验证,得到相同的结果。通过对扭转变形和破坏特点分析,提出了扭转作用中扭锥存在的概念。 In this paper, the method of cross-section stress analysis is used to start from the torsion of the solid circular section, and the formula for calculating the maximum shear stress of the solid circular section is derived, which is in accordance with the formula used at present. Applying this method to the rectangle, the formula for calculating the maximum shear stress of square section twist is obtained and compared with the empirical formula adopted so far to obtain the same result. Through the analysis of torsional deformation and failure characteristics, the concept of torsion cone in torsion is proposed.