Abstract: In order to obtain the practical calculation formula of resistance to lateral stiffness of a new type lightweight composite steel frame wall filled with foam concrete, the monotonic loading test was conducted on DD-1, DD-1 (D-300) and DD-2 (D-400) respectively and the quasi-static loading test was carried out on DZ-1 (D-300) and DZ-2 (D-400) repeatedly. The equivalent tension and compression bars were simplified for the steel mesh skin plate and the equivalent compression bar was simplified for the foam concrete. Using the displacement method to deduce the lateral stiffness calculation formula, and then the DD-1's test results were used to validate the lateral stiffness calculation formula of lightweight composite steel frame wall covered with steel grid skin plate, using the test results of DD-1 (D-300), DD-2 (D-400), DZ-1(D-300), DZ-2 (D-400) to obtain the stiffness correction factor of the equivalent compression bar of foam concrete, and then obtain the lateral stiffness calculation formula for the new composite wall. The results showed that the calculation results obtained by the displacement method were in good agreement with the test results.