In order to study the ability to resist lateral force of nuclear shielding workshop under earthquake action，the low-cyclic loading tests of nine 1/5 scaled composite shear walls with double steel plates and filled concrete were carried out. This paper studied the influence of several parameters such as stud space，thickness of the palate and stiffener on initial lateral stiffness of specimens. The results showed that the initial stiffness of composite shear walls increased with the thickness of steel plates and stiffening rib setting，but the factor of stud space had no obvious effect on it. The calculation formula of initial stiffness of composite shear walls with double steel plates and filled concrete was derived by using unit load method，theoretical hypothesis and simplified precondition. The calculation value was consistent with the experimental value. Moreover，the change process of lateral stiffness of shear wall specimens under cyclic loading was studied and it was found that the changing degree of the stiffness was different in the different stages of the change process of lateral stiffness.