A monolithic integration of the light emitting diode (LED) and photodetector (PD) based on III-nitride is designed and fabricated on a sapphire substrate to act as a transceiver. Due to the coexistence of light emission and detection phenomenon of the multi-quantum well (MQW) structure, the monolithic transceiver can effectively sense environmental changes. By integrating a deformable Polydimethylsiloxane (PDMS) film on the transceiver chip, external force variation can be effectively detected. As the thickness of the PDMS reduces, the sensitivity significantly improves but at the expense of the measuring range. A sensitivity of 2.968 3% per newton for a range of 0–11 N is obtained when a 2 mm-thick PDMS film is packaged. The proposed monolithic GaN transceiver-based sensing system has the advantages of compactness, low cost, and simple assembly, providing an optional method for practical applications.