The utility model relates to a monitor for the water injection system, comprising a water injection pump 1, a water injection pipeline 2, a sensor 3, a monitor 4 and a water distributing station 5. The water injection pump 1, the water injection line 2 and a water distributing station 5 are sequentially connected. A sensor 3 is provided between the water injection pump 1 and the water distributing station 3. The monitor 4 and the sensor 3 are connected by the circuit control. The utility model accurately displays the suction and the discharge pressure of the water injection system through a numerical control instrument, works out the alarm in time when the setting pressure range is exceeded. The person on duty controls the operation state of the water injection system through the display of the meter panel in the duty room, alarms through the abnormal situation of the water injection system, and excludes various failures in time.