Abstract ： Research purposes ： Coulomb active earth pressure is widely applied in construction engineering. Engineers generally use the formulas of manual or code. But these formulas have limitations which are only applied to specific boundary conditions. And in the process of practical engineering design, boundary conditions often break through these specific boundary conditions. At this point, those formulas from manuals or codes are not applicable,and this often brings troubles to the designers. So it is necessary to find a common solution for Coulomb active earth pressure, which can be applied to all kinds of boundary conditions. This paper presented the common solution based on the principle of Coulomb earth pressure and differential principle，which can be used to provide convenience and reference for designers. Research conclusions:( 1 ) This paper presented a general solution for various boundary conditions based on the principle of Coulomb earth pressure and differential principle. （2) Although this method is more complicated，but it is very easy to implement by using computer programming. The calculation process is convenient and quick. ( 3 ) In practical engineering design，especially when the boundary condition is more complicated，using the software based on the general solution of this paper to calculate the Coulomb active earth pressure can have twice the result with half the effort.