Abstract：Fault dislocation due to large earthquake is known very well by people，and geologic disasters induced by fault creep get more attentions gradually. There is a relationship between the seismogenic process of earthquake and a abnormal variation of fault creep rate. The deformation of fault creep is potential threatening to the safety of nuclear power plant，dam of reservoir，lifeline systems of a city，large and high buildings. The technique for automatic measurement of fault deformation is of advantage to investigation in present-day fault activity，earthquake observation and prediction，and engineering safety evaluation. The photoelectric system for fault deformation measurement was developed by the Institute of Crustal Dynamics at the end of the nineties of the last century，with high precision，large ranges and no electricity drift，which adopted a displacement sensor with charge coupled device(CCD) as the key components. This measurement system is reliable，too，for fault movement observation accurately and continuously.
