Abstract: With the increasing and intensive use of underground space in urban construction, in recent years, some actual projects of geotechnical engineering design beyond the scope of the norms and standards are quite common. However, relevant national standards, industry standards and local standards are different in the specific provisions. The active earth pressure calculation of foundation pit side-wall involved in the relevant provisions of some codes and manuals are sorted out and summarized. The principle analysis of an engineering project case is carried out, which often appears recently but has not yet listed specific provisions in various codes. The calculation principle for this kind of working condition is put forward. The purpose is to sort out the terms of active earth pressure calculation on the side-wall of foundation pit clearly, and provide suggestions and supplements for the calculation principle of a working condition not listed in the specifications, so that the relevant problems in the geotechnical engineering design can be carried out clearly and reasonably.