The invention discloses a method for determining the resultant force and the resultant force application point of active earth under common conditions. The method comprises the following steps: 1), determining the geometric elements of a retaining wall and an earth mass behind the wall; 2) determining the physical and mechanical parameters of the wall earth mass; 3) determining the coordinate x1 of the intersection point X of an earth mass sliding surface and a slope curve; 4) calculating the resultant force of the active earth pressure according to the formula Ea=[a1(a-n1)x<2>1/2+b1x1-cx1]/sin(alpha-delta); 5), calculating the pressure resultant force application point of the active earth pressure according to the formula which is defined as the specification. The method conforms with an actual active earth pressure calculating method, accurately and reliably determines the value and the application point position of the active earth pressure and has significant practical significance in the scientific and reasonable guidance of the design of the retaining wall.