Neck protecting device

The utility model relates to a neck protecting device, which comprises an air bag, a steel cylinder containing compressed air and a communicating pipe. A ventilate channel is formed inside the communicating pipe. Communicating mouth is arranged on both end of the communicating pipe, they are provided separately to connect with the steel cylinder and the air bag. A beam is movable insert into the communicating pipe; a plurality of bump receiving devices and an opening are arranged on the beam. The opening is arranged relative to the ventilate channel place in the communicating pipe. When the collision occurs, the bump receiving devices can push the beam to rotate to the opening of the beam communicates with the communicating pipe ventilate channel, thus the compressed air contained in the steel cylinder can be sent to the air bag through the communicating pipe, to make the air bag inflated.