The utility model discloses a liquid pipeline normally-closed valve sealing performance monitoring device, and belongs to the technical field of liquid pipeline valve leakage monitoring. The device comprises a liquid collecting pipe matched with a liquid pipeline, the inner wall of the liquid collecting pipe is provided with an inclined closed liquid guide groove, the liquid collecting pipe communicates with a liquid storage device through a liquid inlet pipe, the liquid inlet pipe communicates with the bottom end of the liquid guide groove, and a liquid level sensor is arranged in the liquidstorage device. The leakage liquid is completely collected by the closed liquid guide groove, and is transmitted into the liquid storage device through the liquid inlet pipe, the liquid level sensor monitors the leakage amount, the leakage liquid is accurately monitored, the structure is simple, the cost is low, the processing is easy, the caliber of the whole valve can be covered, the leakage liquid is completely collected, the monitoring is accurate, the reliability is high, and the groove type liquid guide groove does not generate any resistance influence on the original liquid discharge pipeline.