Monitoring the ground vertical deformation of the large factory in a high precision is an important problem in
precise engineering survey. By the work of monitoring the ground vertical deformation of a large factory in the northwest
loess tableland, this paper puts forward and applies some effective methods and measures for example choosing the typi-
cal monitoring area to set up monitoring points,improving on staff guage and so on. At last satisfactory results are got-
ten. By analyzing the monitoring data,it points out that the leading reason of jig instability is the ground vertical deform-
ation which is caused by temperature changing. This provides grounds for the harnessing of this factory. These methods
and measures are of great reference value for design staff,builders and managers.