The principle of earthquake resistance is to reduce casualties and earthquake damage. In order to achieve this goal, it is necessary to determine the earthquake resistance of existing buildings, which requires seismic identification of the structure, and provides a theoretical basis for earthquake-resistant reinforcement and reconstruction, so that the existing buildings in the process of earthquake-resistant reinforcement more economical and reasonable.When an earthquake occurs, with the vibration of the formation, the seismic effect is passed through the foundation to the main body of the structure.If the main structure does not meet the requirements of anti-seismic fortification, the structure of the house will be seriously damaged. Some of the existing structures were built in the last century, or most did not meet the requirements of the latest specifications, and did not take into account the requirements of earthquake defence.