Through the cavity wall energy-saving test in the experiment, The influence of the maintenance period to the wall of heat transfer coefficient was analyzed, it is found that moisture content was the most important influencing factor. Through contrast to the result of the cavity wall of heat transfer coefficient test and the theoretical calculation, the reason of the different was analyzed, what was the test operation error and the simplified theoretical calculation, and proposed three corrective measures to reduce the influencing factors of the cavity wall heat transfer coefficient experiment, provided a reference for the cavity wall research in the hot summer and cold winter zone.