A side wall cavity (105) detection device and detection method for a
storage tank, relating to the technical field of measurement devices. A tank cover of a
storage tank is provided with a plurality of pipes (102), and each
pipe (102) is in communication with the side wall cavity (105). The side wall cavity (105) detection device comprises: a support main body (20), comprising a telescopic member and a driving member (205), wherein the telescopic member is capable of passing through each
pipe (102) to extend into the side wall cavity (105), and the driving member (205) is used for driving the telescopic member to extend / retract; a detection
system (30), at least comprising a material
detector (304) and a processor (301), wherein the material
detector (304) is used for acquiring distribution state information of a filler material in the side wall cavity (105), and the processor (301) receives and processes the distribution state information of the filler material; and a display
system (40), used for displaying the distribution state information of the filler material processed by the processor (301). By means of the side wall cavity (105) detection device, visualized, full-angle, three-dimensional imaging scan detection results for the side wall cavity (105) of an inspected
storage tank can be efficiently and accurately obtained, meeting the requirements for high-precision and high-efficiency detection of filling state change of the filler material in the side wall cavity (105) of the storage tank.