This paper reports a voltage regulation method with power management to enhance the reliability and stability of the self-powered flow rate sensor. Triboelectric energy harvesters are used both as the sensing signals and the power supply. One channel of the raw voltage from wind flow is regulated to a stable signal by the integral circuit, while the other channel is used for energy harvesting to provide the power for the whole circuit. Power management chip with ultra-low power consumption has been utilized with micro controller unit and antenna for wireless transmission. A low deviation of less than 2.5% has been achieved for the flow sensing signal and the temperature has also been monitored simultaneously, which shows promising application for the central air-conditioning system in smart buildings.