Tester for heat conductivity coefficient of flat plate

The utility model discloses a flat plate heat conductivity coefficient tester which comprises a box body, a heat insulation layer, a hot plate, a driving piece, an adapting assembly and a cold plate, the adaptation assembly comprises a sliding plate, a partition plate and a toothed plate; a connecting column is arranged on the cold plate; a through groove is formed in the sliding plate; a first sliding groove is formed in one side of the penetrating groove. A first tooth block is slidably connected into the first sliding groove. A first spring is fixed between the first tooth block and the first sliding groove. A first rack is arranged on the toothed plate; when the device is used, a to-be-tested flat plate is arranged in the heat insulation layer and is in contact with the hot plate, the driving piece drives the sliding plate, the partition plate and the cold plate to slide, and after the cold plate is in contact with the flat plate, the first rack is pushed to move by a corresponding distance relative to th