Heavy oil underground sampling device

The utility model provides an underground heavy oil sampling device. A sample cylinder is used for containing a fluid sample in a well; a sampling hole is axially formed in the head end joint; a central inner hole is formed in the axial direction of the control pup joint, and four sample inlets are formed in the side direction; a lead screw is mounted at the upper section of a central inner hole of the control pup joint; the lower section is provided with a sealing plunger; the upper end of the lead screw is connected to a micro motor; the micro motor is controlled by the circuit module; the lead screw is driven to rotate forwards or reversely; forward and reverse rotation of the lead screw drives the sealing plunger to move up and down; when the lead screw rotates in the forward direction, the sealing plunger moves upwards to the limit position, the lower end face of the sealing plunger is away from the upper end face of the sample injection hole, a fluid sample enters an inner cavityof the sample cylinder t