Abstract: In order to solve the technical problem of compactness detection of mass concrete, a new nondestructive testing technology of acoustic scattering concrete scanning (Cscan) imaging was proposed. Cscan technology and its characteristics were explained in detail by covering basic principles, field collection, data processing and engineering interpretation of results. To verify the accuracy of this method, a test for the compactness of concrete in a liquified natural gas (LNG) storage tank foundation pit was carried out. The test results show that the Cscan technology has high detection accuracy for mass concrete, and has a good application effect in the field with only a single measurable surface.