As the increasingly harsh conditions of deep excavation in urban area, two or more different depths of excavation in one foundation pit are becoming more common. Ignoring the influences caused by two different asymmetric excavations, traditional method to solve this problem is simplifying the asymmetric excavation as symmetrical and using the deeper side in calculation. Given that, analytical solutions for the length of retaining structures in foundation pit considering the influences caused by two different asymmetric excavations have been deduced using the equivalent beam method. The influences on differences between retaining structures on two sides and their insertion ratio caused by two different asymmetric excavations have been investigated. The results show that, considering two different asymmetric excavations, insertion ratio of retaining structures located on the side of pit with shallower depth increases compared with calculating results without considering two different asymmetric excavation. This enhancing effect of insertion ratio becomes more obvious as the depth of deeper side of the excavation increases. Finally, a case study proved that the analytical solutions can improve the asymmetric excavation pit design method, and provide a useful and economic reference.