The invention discloses a piston roll riveting device of a pinion-and-rack steering machine. The piston roll riveting device of the pinion-and-rack steering machine comprises a rack shaft sleeved with a piston and a supporting shaft, and the supporting shaft is provided with a limiting base used for limiting one end of the gear shaft, an automatic reset device and a supporting base for supporting the rack shaft. The rack shaft is sleeved with a limiting sleeve attached to one end of the piston, the two sides of the piston and the two sides of the limiting sleeve are respectively provided with extrusion wheels arranged on a roll riveting machine, and the extrusion wheels are provided with extrusion grooves matched with the limiting sleeve and the piston. According to the piston roll riveting device of the pinion-and-rack steering machine, the automatic reset device is adopted, when the rack shaft and an idler wheel are different in center height, automatic center height adjustment and resetting can be performed when roll riveting is performed on the piston through the roll riveting machine, and operability is good; meanwhile, the limiting sleeve is used for limiting, and piston locating is accurate.