The invention discloses a spindle seal monitoring device. The spindle seal monitoring device comprises a shell. A spindle is arranged at the inner bottom of the shell in a penetrating mode and rotationally connected with the lower end of the shell. An abrasive disc is fixedly connected with the upper end of the spindle. L-shaped plates matched with the edge of the abrasive disc are arranged on theopposite inner walls of the shell correspondingly. Monitoring device bodies are arranged on the sides, located on the abrasive disc, of the L-shaped plates. Each monitoring device body comprises a cylinder fixedly connected with the side wall of the corresponding L-shaped plate; a pressure detecting device is fixedly connected with the inner wall of each cylinder; a movable rod is arranged in each cylinder and fixedly connected to the side wall of the corresponding pressure detecting device through a first elastic device; and strip-shaped grooves are arranged in the opposite inner walls of each cylinder correspondingly. The spindle seal monitoring device is simple in structure, the leakproofness of the monitoring device can be monitored in real time, the effect that the monitoring devicecan be maintained in time when the monitoring device breaks down is ensured, and safe and efficient operation of the monitoring device is ensured.