Anti-freezing and anti-thawing device for road and railway roadbeds

The utility model provides a road and railway roadbed freeze thawing prevention device which comprises a drain pipe, the drain pipe is buried in a road or railway roadbed, drain holes are evenly formed in the surface of the drain pipe, a first air bag is arranged in the drain pipe, and the side end of the first air bag is fixedly connected with a nitrogen storage steel cylinder through a first connecting pipe. A first one-way valve is arranged on the first connecting pipe, a second air bag is fixedly connected to the other end of the nitrogen storage steel cylinder through a second connecting pipe, a first electromagnetic valve and a second one-way valve are arranged on the second connecting pipe, the second air bag is communicated with the first air bag through an air bag pressure pipe, and a second electromagnetic valve and a third one-way valve are arranged on the air bag pressure pipe. The pressure in the drain pipe is changed through inflation and deflation of the air bag, water in the roadbed enters the