The wire failure data of domestic civil aircraft are difficult to obtain because of the unsound collection system. To solve the problem of data acquisition, a construction method of improved model is proposed based on expert experience for the safety basic data of wiring. Firstly, a wire failure model is built based on the analysis of wire failure modes considering the correlation among the environment variables. Then, the typical failure environment, severity of environmental variables and correlation among environment variables are judged by selected experts in the field when typical failure environments applied to all domestic civil aircraft models are determined, and the effectiveness and consistency of judgment are checked. The model parameters are solved according to the results of expert judgment based on preferred paired comparison model. The results demonstrate the proposed model can pass the test and has good fitness. Finally, the wire failure model is amended by actual failure rate obtained from actual statistical data.