Gas insulated bus contacts are the frequent parts of overheating faults, and the size of contact resistance is the decisive factor for the stable operation of the equipment. In order to predict the contact failure of GIB contacts, a failure prediction model of gas insulated bus contacts is established in this paper based on the nonlinear Wiener model of time scale and the inverse power rate accelerated aging model. A test platform for electric contact failure of gas insulated bus contacts was set up, and a test of current-carrying friction and wear of gas insulated bus contacts under SF6 and air media was carried out. The contact resistance degradation expression of gas insulated busbar contacts under different conditions is obtained by the likelihood function parameter estimation. The comparison between the test results and the prediction results shows that the proposed failure prediction model is effective.The service life of GIB contacts under air is 22.76 years, and the service life under SF6 is 43.67 years. The failure prediction model established can provide technical support for the design, manufacture and maintenance of GIB contacts.