The invention discloses an automatic measuring instrument of multilayer location, and a measuring method. The automatic measuring instrument of multilayer location comprises a monitoring computer, a drive electric motor, a guide rail, a slide block, a limit switch, a pressure sensor, a probe rod and a floater, wherein, the computer is connected with the pressure sensor, the limit switch and the drive electric motor; the limit switch is arranged at the upper end of the linear guide rail, the drive electric motor drives the slide block to move along the guide rail, and the probe rod is arrangedon the pressure sensor fixed on the slide block. The automatic measuring instrument of multilayer location of the invention can realize the location measurement not only of multilayer materials, but also under conditions of severe pollution, high temperature, mass mill dust and indistinct interface, etc.