Environment monitoring instrument used in severe environment

The utility model discloses an environment monitoring instrument used in a severe environment, which comprises an environment monitoring instrument, a connecting rod fixed at the bottom and a chassis, the top of the chassis is rotatably connected with a threaded sleeve, one end of the connecting rod is in threaded connection with the threaded sleeve, an expansion assembly is arranged in the chassis, and the expansion assembly comprises a driving wheel. Four first driven wheels are arranged outside the driving wheel, second driven wheels are arranged on the sides, away from the driving wheel, of the four first driven wheels, first transmission wheels and second transmission wheels are fixedly arranged on the sides, close to the chassis, of the first driven wheels and the second driven wheels, and transmission belts are arranged on the peripheries of the first transmission wheels and the second transmission wheels; sliding grooves are formed in the sides, close to the second transmission wheels, of the chassis,