Lightweight steel rail milling and grinding vehicle

A lightweight steel rail milling and grinding vehicle comprises a milling operation vehicle and a grinding operation vehicle, and the milling operation vehicle comprises a milling vehicle body, a walking part and a milling device; the milling devices are arranged on the left side and the right side of the milling vehicle body and mill steel rails on the two sides of the track correspondingly. The polishing operation vehicle comprises a polishing vehicle body, a walking part, a polishing device, a dust collecting device and a power unit. Polishing devices are arranged on the left and right sides of the polishing vehicle body; the dust collecting device is arranged on the polishing vehicle body; the power unit provides electric energy for the walking part; the walking part comprises an axle tube, an axle, a motor, a speed reducer, a mounting disc and wheels; the axle tube is mounted at the bottom of the corresponding vehicle body through a primary suspension; an axle is arranged in the axle pipe in a penetratin