The invention discloses a detection mechanism which comprises a detection bracket (j1), a detection support frame (j2), an upper compression component (j3), a lower compression component (j4), a detection component (j5), a detection tray (j6) and a raceway (j7). The detection bracket (j1) is used for carrying the other components; the detection support frame (j2) is used for carrying the upper compression component (j3), the lower compression component (j4) and the detection component (j5); the upper compression component (j3) can be separated from workpieces carried on the detection tray (j6) or can compress one surface of each workpiece carried on the detection tray (j6); the lower compression component (j4) is used for jacking the other surface of each workpiece carried on the detection tray (j6); the workpieces can be carried by the detection tray (j6), and the detection tray (j6) can approach the detection component (j5) or get away from the detection component (j5). The detection mechanism has the advantages that the workpieces can be accurately and efficiently measured by the detection mechanism, accordingly, the dimensional consistency of the workpieces can be guaranteed, the detection mechanism can be operated with a mechanical arm and is high in automation degree, and the workpieces can be prevented from being scratched.