Abstract: According to the specifications of American and Chinese design for structural steel， a detailed introduction is provided on the methods for structural steel stability design. There are some design methods in the two specifacations， with similarities and differences between them. In order to deepen understanding of the direct analysis method and promote its further application in practical engineering， this study focused on a comprehensive comparison of the direct analysis method between the two specifications. The comparison showed significant differences in the methods used to address the P-Δ and P-δ effects. The American. specification offers more practical convenience in application but lacks sufficient theoretical basis in some aspects. Although the Chinese specification has strong theoretical support， its practical application is sometimes cumbersome， and some details are not yet clear. Meanwhile， a simple comparison was conducted between the direct analysis methods of the two specifications through a calculation example. The results showed little difference in internal force calculations between the two methods. However， in terms of horizontal drift， the results obtained using the American specification were greater than those from the Chinese specification.