With the safe operation of the whole wind turbine generator to be paid more attention, the reliability of the ultracapacitor modules for wind turbine pitching has become more and more important. For continuously monitoring to the health status of the ultracapacitor modules and ensuring the reliability, this paper presents an on-line monitoring method of the health state of the module. When wind turbines LVRT and feathering after power down, it can measure the electronic quantity that the ultracapacitor discharges respectively by open circuit voltage measurement methods and current integral measurement methods in the master system. The ratio of the difference of the calculated electronic quantity to the failure thresholds of the ultracapacitor module determines the health state of the ultracapacitor module. Experimental results show that the master-controlled system can monitor the ultracapacitor module health status by the above methods, particularly when the ultracapacitor aging failure occurs, this method can continuously effectively monitor the health status of the ultracapacitor for wind turbine pitching, thus improve the reliability of wind turbines for safe operation. This work is supported by National Natural Science Foundation of China (No. 51207048).