For solid tantalum capacitors with 3,4-ethylenedioxythiophene (PEDOT) conductive polymer, temperature and humidity are used as accelerated test stresses in this paper. Variable interval measurement method is used to build a constant stress accelerated degradation test platform for tantalum capacitors under four stress levels, which are 85℃ / 85% RH、95℃ / 70% RH、 95℃ / 85% RH、 110℃ / 85% RH. Degradation data of the performance degradation parameters capacitance and loss factor are obtained. Aiming at the non-single change trend of the degradation parameters of tantalum capacitor under accelerated stress of temperature and humidity, ordered clustering algorithm is used to divide the degradation interval. Optimal classification number is determined by the change rate of error function slope, and the stable degradation interval of tantalum capacitor is obtained. Based on data reconstruction and Wiener process, the capacitance and the dissipation factor are fitted and the fitting accuracy reaches 97% and 95% , respectively. As a result, the effectiveness of Wiener process model is verified. Combined with Copula function, a binary accelerated degradation model of tantalum capacitor based on random effect Wiener process is established. Reliability evaluation method is researched and the product life under normal stress level which meets the product life requirement of 12 ~ 15 years is deduced. Results show that the binary accelerated degradation model can finish degradation performance analysis and life prediction of tantalum capacitor.