Sound insulation guardrail for expressway

The utility model discloses a sound insulation guardrail for an expressway. The device comprises a mounting base and a machine body, mounting grooves are fixedly formed in the two sides of the mounting base correspondingly. A clamping groove is formed in the top of the mounting base; two first sliding grooves are evenly formed in the bottom of one side of the machine body. Fixing blocks are fixedly arranged at the four corners of the bottom of the machine body. Cavities are formed in the two sides of the bottom end of the machine body. Spring rods are fixedly arranged at the top ends of the two cavities; extension plates are fixedly arranged at one ends of the two spring rods respectively; the outer walls of the two extension plates are connected with the inner walls of the two cavities ina sliding mode respectively, and a plurality of sound absorption holes are fixedly formed in one side of the machine body. When the sound insulation guardrail for the expressway is installed, the requirement for labor force