Abstract: With the increasing demand of sensor self-power supply device under the information age and the aggravation of global warming and environmental problems caused by the use of traditional fossil energy, it is urgent to come up with new energy utilization and power generation ways. As a passive, zero-carbon and negative heat energy conversion method, hydrovoltaic power generation can make full use of the water cycle in nature and has significant research value. In this paper, moisture induced hydrovoltaic technology is chosen as the energy utilization form and graphene oxide (GO) was used as the raw material. Through the self-polymerization reaction of dopamine, part of the raw material could be reacted to reduced grapheme oxide (rGO), and the freeze-drying and tableting were combined to fabricate the Janus hydrovoltaic GO-rGO composite material. The as-prepared material has obvious characteristics of gradient distribution of oxygen-containing functional groups and can generate electricity for a long time under high humidity conditions, the output voltage of a single hydrovoltaic device is nearly 400 mV and the peak power density is up to 25 μW/cm³. Besides, it exhibits excellent stability which still maintain good output performance after 1 year. More importantly, this generator can be arrays in series to further improve the generation property for driving low-power devices and responding the expiration-inspiration behavior, the output voltage of 8 devices in series can easily reach to 3 V. The as-prepared moisture hydrovoltaic material and generator have the advantage of simple preparation method and excellent output performance, thus showing good application prospect in the field of self-power supply and sensing.