Method and system for automatically monitoring vertical displacement of oil and gas pipeline in frozen soil region

The invention provides a method and a system for automatically monitoring vertical displacement of an oil and gas pipeline in the frozen soil region. The method is characterized in that a long-time stable monitoring reference point is arranged outside a pipe trench; a plurality of monitoring points are arranged on a pipe body; osmometers are fixed in the reference point and the monitoring points on the pipe body and are connected to a liquid tank by a liquid communicating pipe; the osmometer fixed in the reference point is used for measuring the liquid pressure in the position of the osmometer fixed at the reference point, the osmometers in the monitoring points are used for measuring the liquid pressure of the elevations on which the osmometers in the monitoring points are located and the elevation differences between the reference point and the monitoring points are calculated; when a pipeline sinks or uplifts, the new elevation differences are calculated by measuring the liquid pressure, thus calculating pipe elevation variation; and pipeline elevation variation in each monitoring point can be obtained by periodically measuring the liquid pressure in the reference point and each monitoring point by the osmometers. The method and the system are suitable for large-range automatic monitoring of vertical displacement of the oil and gas pipeline in the frozen soil region in large-fall regions.