The three-dimensional heat transfer performance of the slotted light steel-framed composite wall atminimum temperature is simulated using the finite element software of ANSYS. Based on the simulatedresults of heat transfer and the theory of moisture permeation, moisture transfer of the composite wall iscalculated. The results show that there is no condensation at the inner wall surface at the minimumtemperature in Harbin when the thickness of the wall is 229mm. The condensation may occur in the rockwool near the outer wall. However, there is no moisture accumulation in rock wool during heating period.