In the environment of deregulated electricity retail market, the improvement of power supply service quality has become the key means for power supply companies to stay competitive and develop in the new round of power reform. An evaluation index system of power supply service quality is constructed under the deregulation of electricity retail market. Aiming at the service quality of power supply companies, a dynamic comprehensive evaluation method based on double inspiriting control lines is proposed. Based on the traditional static evaluation method enforced by weighting method, the temporal variations of power supply service quality in time sequence are also taken into consideration.With introducing the“reward and penalty mechanism”, the power supply service quality can be dynamically evaluated. Modeling and simulation results show that the index system and evaluation method can facilitate power supply companies to percept their market state, and help them to improve the level of the integrated power supply service quality.