The invention discloses a hardness measuring device for automobile part production based on a Rockwell hardness tester, and relates to the technical field of automobile part production. The hardness measuring device for automobile part production based on the Rockwell hardness tester comprises a mounting box, wherein a mounting box is welded and mounted at the bottom of the inner side of the mounting box; and a mounting block is welded and mounted at the bottom of the inner side of the mounting box. Through cooperative use of a fixing plate, a second sliding block, a hydraulic rod, a crossingblock, a hinge rod, a first clamping block, a second clamping block, a first vertical block, a second vertical block, a clamping block, an inserting block and an inserting rod, two groups of automobile parts can be clamped and fixed at the same time; on one hand, a worker does not need to hold the automobile parts by hands for hardness measurement; on the other hand, two groups of measurement values can be obtained through the arrangement of the two groups of automobile parts for comparison, so that the possibility of measurement errors is reduced; and the automobile parts with different sizesand different shapes can be fixed, so that the error-tolerant rate of the device is further enhanced.