Alarm for monitoring sucker rod off-doffing card

Disclosed is an oil field rod parting monitoring alarm which comprises a loading pressure sensor, an elbow, a pressure gauge joint, a shockproof electrical contact pressure gauge, a relay, a DC power supply and an alarm transmitter; a polished rod through hole is arranged in the middle of the loading pressure sensor and connected with the shockproof electrical contact pressure gauge through the elbow and the pressure gauge joint; the low pressure contact and the high pressure contact of the shockproof electrical contact pressure gauge are connected with the cathode of the DC power supply; the relay coil is in serial connection between the pointer contact and the anode of the DC power supply; the power line of the alarm transmitter is connected with the power supply through the normally closed contact JB of the relay; meanwhile, the AC contactor coil of the motor control cabinet or the power line of the motor protector is in serial connection with the normally closed contact JB of the relay. When the oil rod p