The arch axis combination method of approximate analytical solution for rational arch axis under muti- type loads was proposed in this paper as there was no general method solving this problem. Based on the analy- sis of multi-type loads， the multi-type loads were firstly divided into a series of single type loads， and then the analytical solution for rational arch axis and horizontal thrust was deduced in every single type load; according to the contributions to total horizontal thrust， a linear combination of these rational arch axes was the approximate analytical solution for muti-type loads. Based on the basic principles of mathematics and mechanics， the pro- posed method was verified through the deduction of three aspects for single type load mathematical function. By taking several typical deduction work of rational arch axis under muti-type loads as examples， the universality and accuracy of proposed method were tested from the aspects of pressure line coordinates， main arch bending moment and horizontal thrust. The research results show that approximate analytical solution of rational arch axis can be easily deduced by the proposed method， which is of great universality; axis deviation between approxi- mate analytical solution and actually rational arch axis is very small， and the bending moment of main arch ring is close to zero; the horizontal thrust is a precise solution under continuous loads， and the continuous transfor- mation of discrete concentrated force will bring some small errors in horizontal thrust of the proposed method.