Abstract: Since dam-CT can monitor the dam′s deep interior fast and nondestructively,the technique has been receiving increasing emphasis.This paper introduces the techniques of dam-CT that are based on detection of the distribution of elastic waves,electromagnetic waves and electric resistance.In particular,research advances in the relatively mature area of acoustic-wave dam CT is reviewed with respect of its feasibility,the working principles,hardware equipment and software techniques.Key problems and the development trend of the acoustic-wave dam CT research are discussed.