Suitable optoelectronic integration platforms enable the realization of numerous application systems at the chip scale and are highly anticipated in the rapidly growing market. We report a GaN-on-silicon-based photonic integration platform and demonstrate a photonic integrated chip comprising a light source, modulator, photodiode (PD), waveguide, and Y-branch splitter based on this platform. The light source, modulator, and PD adopt the same multiple quantum wells (MQWs) diode structure without encountering incompatibility problems faced in other photonic integration approaches. The waveguide-structure MQW electro-absorption modulator has obvious indirect light modulation capability, and its absorption coefficient changes with the applied bias voltage. The results successfully validate the data transmission and processing using near-ultraviolet light with peak emission wavelength of 386 nm. The proposed complete active–passive approach that has simple fabrication and low cost provides new prospects for next-generation photonic integration.