Abstract: In order to evaluate the safety status of transmission lines scientifically and objectively，a safety

analysis model of transmission lines based on support vector machine-back propagation（SVM-BP）hybrid network

was proposed. Firstly，the weather data，transmission line standard documents and defect data were processed and

analyzed，and the defect data of transmission lines were integrated by association rules and principal component

analysis，and the safety status evaluation system of transmission lines was established. Then，the SVM-BP hybrid

network model was proposed to mine the correlation between each factor and the defect state，and evaluate the

security state of the transmission line. Finally，the accuracy of the evaluation model is 97.4% when the transmission

line in a certain region was used as the data set to verify. It can evaluate the safety state of transmission quickly and

accurately，and take countermeasures in advance under disastrous weather to ensure the stable operation of

transmission line.

      Key words: transmission line；association rules；principal component analysis（PCA）；support vector machineback propagation（SVM-BP）