According to the DBSCAN algorithm shore bridge state classification method based on principal component analysis, sensors are installed at all positions of a shore bridge, and data transmitted by thesensors are extracted at set time intervals; Through principal component analysis, after data centralization, a characteristic covariance matrix and characteristic values and characteristic vectors thereof are obtained, the contribution degree of each component is calculated, and a plurality of previous-order principal components are taken to carry out matrix transformation; And initializing a density threshold value and a density radius for data point clustering, realizing shore bridge state classification according to a clustering result, and realizing shore bridge state monitoring. Accurateand rapid clustering of the quay crane state is achieved, non-circular domain distribution data can be clustered, a good effect is achieved, compared with a common DBSCAN algorithm, time complexity is reduced, clustering efficiency and accuracy are improved, and abnormal data can be well recognized.