The invention discloses a compression detection device for a fabricated building connection structure. The device comprises an operation table, a first spring, a threaded rod, a guide chute and a connecting piece body; a support rod is fixed on the operation table, an electric telescopic rod is fixed on the operation table, and a movable frame is fixed at the tail end of the electric telescopic rod; and meanwhile, a lower sliding plate is fixed to the lower end of the movable frame, a limiting top plate is fixed to the tail end of the sliding block, a second gear is fixed to a partition plate through a bearing, the connecting piece body is arranged on the movable frame, and the connecting piece body is arranged below the limiting plate. According to the compression detection device for the fabricated building connection structure, the sliding frames moving in opposite directions are adopted and matched with elastic limiting mechanisms, so that connecting pieces with different sizes and thicknesses can be limited and fixed, the detected piece is prevented from moving in the detection process, and the diameter of a top pressing plate is adjusted by adopting an adjustable structure; therefore, the influence effect of different extrusion areas on the detected piece is achieved, and the accuracy of detection data is ensured.