The utility model discloses a water stealing prevention device for a meter-free danger prevention gate, which comprises a valve body, a
gate valve gland, a gate head, a sensor, a
remote terminal unit (RTU) connected with the sensor and a
computer management module connected with the RTU through
wireless signals, the
gate valve gland is mounted at the top end of the valve body, the sensor is mounted on the
gate valve gland, and the
computer management module is connected with the RTU through
wireless signals. The sensor is installed on the gate valve gland, the gate head is installed on the gate valve gland and covers the sensor, an induction
magnet which corresponds to the sensor and can be sensed by the sensor is arranged on the inner top wall of the gate head, and when the meter-free danger prevention alarm valve is in a
closed state at ordinary times, the induction
magnet on the gate head is located over a main contact of the sensor. The main contact senses the existence of the induction
magnet and monitors the displacement condition of the induction magnet at any time. When the gate head is rotated to open the valve, after the main contact of the sensor monitors the displacement generated by the induction magnet, the RTU sends a gate opening
alarm signal to the
computer management module, so that the opening state of the valve is fed back in time, and the water stealing behavior is effectively prevented.