Sampling device for oil extraction in oil field

The sampling device comprises a bottom plate, a top plate and four supporting columns, the top ends of the four supporting columns are fixedly connected with the four corners of the bottom end of the top plate respectively, the bottom ends of the four supporting columns are fixedly connected with the top end of the bottom plate, and a lifting mechanism is arranged at the bottom of the top plate. The lifting mechanism comprises a movable plate and a limiting plate, a sampling mechanism is arranged at the top end of the movable plate and comprises a sampling barrel and a sealing cover, jacking force is applied to a connecting rod through a piston rod of a first electric telescopic rod, so that the connecting rod is stressed, the movable plate is driven to descend through the limiting plate, and an oil inlet pipe can extend into an oil well; and then piston rods of two second electric telescopic rods simultaneously drive a pressure rod to move upwards, and meanwhile, the pressure rod drives a movable rod and a s