The invention discloses an online estimation method for service life of a super capacitor, which comprises the following steps: establishing a dynamic model of a super capacitor, the dynamic model comprising the equivalent resistance and equivalent capacitance of the super capacitor; establishing a voltage parameter identification rule of the super capacitor according to the dynamic model, and establishing a self-adaptive method for online estimation of equivalent resistance and equivalent capacitance of the super capacitor according to the voltage parameter identification rule to realize online estimation of the equivalent resistance and the equivalent capacitance and obtain an estimated resistance value and an estimated capacity value; based on a Lyapunov stability theory and a convergence principle, analyzing the stability and convergence of the super capacitor equivalent resistance and equivalent capacitance online estimation adaptive method. According to the self-adaptive method,the service life of the super capacitor is estimated online according to the estimated resistance value or the estimated capacity value, the accuracy of service life online estimation is guaranteed. Compared with an existing online estimation method, the calculation amount is obviously reduced, and a large amount of manpower and material resources are saved.