To achieve reliable flexibility and acceptable transparency for integrated electronics, the power supply sources of these devices have to meet the requirement of flexibility and transparency. Herein, we developed a facile and non-toxic way to manufacture all-solid-state supercapacitors with high capacitive performance, transparency and flexibility. The as-prepared g-C3N4 nanowires are distributed in Polyvinyl Alcohol (PVA) and Poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT:PSS) solution, transparent film could be formed by vacuum filtration. The g-C3N4 nanowires provide pseudocapacitance and PVA and PEDOT:PSS matrix provides bendable and stretchable ability. The g-C3N4/PVA electrode achieves a specific areal capacitance of 3.51[Formula: see text]mF[Formula: see text]cm[Formula: see text] with transparency of 85%, and that of g-C3N4/PVA/PEDOT:PSS is 5.32[Formula: see text]mF[Formula: see text]cm[Formula: see text] with transparency of 72%. The facile process provides a reasonable architecture for the preparation of a variety of flexible, transparent and wearable electronic devices. The flexible and transparent devices show an instant response to the finger bending with the capacitance change of more than 25%, which provides the possibility for fabricating smart flexible device to monitor human health and motion detection.