For long-span suspension bridge, in order to evaluate the expansion function of bridge more accurately and discover the disease in time, based on the general evaluation method of expansion joint and bearing status based on monitoring data, the evaluation of expansion joint and bearing are integrated, and a status evaluation method based on the monitoring data for key restraint devices of suspension bridge is proposed. Wavelet separation method is used to separate the displacement data. The consistency of temperature displacement and the variation range of data details of suspension bridge are analyzed. After segmenting the natural day reasonably, the correlation analysis and break analysis of temperature and displacement are carried out in each continuous period. The method is used to evaluate a large suspension bridge, and the evaluation results are compared with the results of special inspection in the same period. The results show that the evaluation method is reasonable and feasible, which can assist the status evaluation of key restraint devices of suspension bridge.