The invention discloses a single-hole underground water seepage vector monitoring device. The single-hole underground water seepage vector monitoring device comprises an auxiliary material, a vector tracking mechanism, a position monitoring assembly, a device reset mechanism and a main control circuit board; the auxiliary structure supports the vector tracking mechanism, the position monitoring assembly, the device reset mechanism and the main control circuit board; the main control circuit board is connected with the device reset mechanism and the position monitoring assembly; the device reset mechanism is connected with the vector tracking mechanism; the vector tracking mechanism has magnetization characteristic; the vector tracking mechanism horizontally moves along the seepage of the underground water; the position monitoring assembly monitors the motion vector data of the vector tracking mechanism and transmitting the motion vector data to the main control circuit board; after one-time measuring period is completed, the main control circuit board resets the vector tracking mechanism by controlling the device reset mechanism and enters the next measuring period. The single-holeunderground water seepage vector monitoring device can measure the flow speed and the flow direction of the underground water at the measuring point position simultaneously, and can control reset torealize repeated and continuous measurement.