The utility model discloses a concrete structure surface layer hollowing defect detection device. The device comprises a housing, the non-contact heating device is used for heating a to-be-measured area on the surface layer of the concrete structure; the thermal imager is used for detecting that the surface layer of the concrete structure passes through a heating area, the non-contact heating device is installed and fixed in an open heating cavity of the shell and faces a target concrete structure surface layer area covered by the heating cavity, and the peripheral wall and the bottom of the heating cavity are composed of asbestos heat insulation plates; the thermal imager is installed and fixed in the detection cavity of the shell and faces the surface layer area of the target concrete structure, the peripheral wall and the bottom of the detection cavity are made of metal, and a heat dissipation pane is reserved. And the heating cavity is positioned in front of the detection cavity and is provided with 20-30 heat insulation belts made of heat insulation asbestos.