Auxiliary supporting device of large heavy-duty machine tool

The utility model relates to an auxiliary supporting device of a large heavy-duty machine tool. The auxiliary supporting device consists of an oil cylinder, a supporting sleeve, a roller support, a support, a base, a shaft I, a bearing, a roller and a shaft II, wherein the support is arranged on the base, the oil cylinder is installed at the other end of the base, the supporting sleeve is installed on the oil cylinder, the roller support is installed between the supporting sleeve and the support, and the roller is arranged on the roller support. One end of the roller support is installed on the support through the shaft II, and the roller support uses the shaft II as a rotary shaft for rotation of the roller support under the effect of the oil cylinder. The bearing is installed and fixed in the roller through the shaft I, an assembly consisting of the shaft I, the bearing and the roller is installed on the roller support through the shaft I, and synchronous rolling of the roller and a workpiece is ensured whe