The research in this paper is part of wet-sieving concrete technique for building thermal insulated reinforced concrete composite wall. The carbonized depths of fine aggregate concrete and ordinary concrete were measured by the carbonization test method. Based on the test, in standard test environmental conditions, the carbonization changes of fine aggregate concrete rely on its inherent combination changes. The lower carbonized depth takes place in fine aggregate concrete comparing with ordinary concrete, which is resulted from the increasing cement content and the reduction of grain size of coarse aggregate in fine aggregate concrete. Finally, the carbonization of fine aggregate concrete is evaluated according to the relative specification, and the reasonable service life of fine aggregate concrete is precast.