A supporting roller of a scale breaking withdrawal and straightening machine is used for the scale breaking withdrawal and straightening machine. A space ring is installed on a shaft, the two sides of the space ring are respectively provided with a needle bearing, an outer sleeve is arranged outside the space ring and the needle bearings in an interference fit mode, races are installed in the step position of an inner hole of the outer sleeve and on the two sides of the needle bearings, a thrust roller bearing and a shaft washer are sequentially fixed to the outer side of each race, an O-ring and a first sealing ring are installed between each shaft washer and the shaft, an O-ring and a first sealing ring are installed between each shaft washer and the outer sleeve, gaskets are arranged between the first sealing rings, check rings for holes are clamped in the step positions of the outer side of the inner hole of the outer sleeve, check rings for shafts for preventing the shaft washers from moving axially are fixed into positioning grooves of the shaft, and second sealing rings are installed in shaft shoulders of the shaft. Because the structural form that the needle bearings are used for bearing radial force, the thrust roller bearings are adopted at the two ends to bear axial force, and rigid sealing and rubber sealing are combined is adopted for the supporting roller of the scale breaking withdrawal and straightening machine, the supporting roller is good in manufacturing accuracy, rotation accuracy and abrasion resistance, high in stability in use and reliable in sealing, and meanwhile machining and assembling efficiency and assembling accuracy can be effectively improved.