本文用李兹法导得了梁柱弹性弯扭屈曲临界条件的一般方程,并且将其临界荷载用临界弯矩表达,而不用临界压力表达,这是与传统的方法有所不同的。利用这个表达式,来研究梁柱的弹性弯扭屈曲更直接、更简单。而且某些问题用其他方法来求解,很困难时,采用本文方法来求解,则很容易。这就是这种方法更为有用之处。 In this paper, the general equation of elastic-torsional buckling critical conditions of beam-column is derived by using the Liz rule, and the critical load is expressed by the critical moment, without using the critical pressure, which is different from the traditional method. Using this expression, it is more direct and simple to study the flexural-torsional buckling of beams and columns. And some problems are solved by other methods. When it is difficult, using the method of this paper to solve is very easy. This is where this method is more useful.