Sealed pile foundation mud sampling device

A sealed pile foundation mud sampling device comprises a tray, a steel bar, a measuring rope, a first magnet disc, a connecting rod and a mud storage barrel with an opening in the lower end, the steel bar is connected to the lower end face of the tray, a groove is formed in the center of the upper end face of the tray, a protruding block is arranged in the center of the groove, and the protruding block is connected with the steel bar. The protruding block is sleeved with the first magnet disc, the peripheral face of the first magnet disc abuts against the inner wall of the groove, the slurry storage barrel is located over the first magnet disc, the connecting rod is located in the slurry storage barrel, the upper end of the connecting rod is connected to the upper end of the slurry storage barrel, and the peripheral face of the connecting rod is slidably connected with a second magnet disc; the second magnet disc and the first magnet disc repel each other in the same polarity, a slurry discharging hole is for