Abstract: The article emphasizes the study on the p roblem, whose dry shrinkage and cold shrinkage lead to SMC light2weight wall panel cracking from the structure on joint p lace. Mechanism and p revention2and2cure solu2 tion of cracking are researched systematically in this article. This paper refers to the measuring result of elastic modulus of light2boned concrete materialwhich is p rovided by China building2material academey, and finds out the big difference of dynamical character between 2 types of different materials ( SMC light2weight wall panel and the high2intensity concrete) is one of the mostmajor factors leading to cracking on joint p lace. And the change of sur2 rounding humidity is the p rimary factor leading the light2weightwallmaterial dry shrinkage.