The invention relates to a measurement mechanism. A sample multipoint measurement mechanism is characterized by comprising a group of longitudinal guide rails, longitudinal cylinders and longitudinal sliding blocks, which are arranged in a zygomorphy way, as well as two groups of horizontal guide rails, one group of horizontal cylinders (52 and 53) and one group of horizontal cylinders (52' and 53'), which are arranged in a longitudinal symmetry way. The group of longitudinal guide rails and longitudinal cylinders are fixedly connected on a vertical plate, the longitudinal sliding blocks driven by the longitudinal cylinders are respectively arranged on the longitudinal guide rails up and down, meanwhile, the longitudinal sliding blocks are respectively provided with two groups of horizontal guide rails which are arranged in a longitudinal symmetry way; the two groups of horizontal guide rails are respectively provided with three horizontal slide blocks which form a group; the corresponding two groups of horizontal sliding blocks are respectively provided with a sensor; and two groups of horizontal cylinders arranged up and down are respectively connected with matched horizontal sliding blocks. By utilizing the accurate driving of a multistage cylinder, the mechanism moves the sensor fixed on the multistage cylinder so as to achieve the multipoint measurement of sample dimension.