The invention discloses a fixed supporting beam vibration electromagnetic self-powered microsensor in a radio frequency receiving and transmitting assembly of the Internet of Things. The two energy collecting self-powered modules of a piezoelectric transducer and a rectifying antenna system are integrated, and the functions of collection, conversion and energy storage can be respectively achieved on mechanical vibrational energy and stray electromagnetic energy. Gallium arsenide is used as a substrate, and the microsensor is composed of an MEMS fixed supporting beam, a filter circuit, a rectifying circuit and an energy storage capacitor. Fiver layers of an upper electrode, a piezoelectric film, a lower electrode, a silicon nitride dielectric layer and a rectangular microstrip patch antenna are arranged on the MEMS fixed supporting beam from top to bottom. Integration of the two modules can complement each other, the microstrip antenna structure is used as inertia force and deformation of mass block reinforcing beam vibration, and the directivity range of energy collecting by the microstrip patch antenna can be widened along with vibration of the beam. Energy collecting efficiency and power supply capacity are improved, the effective scheme is provided for solving the self-powered problem of a low-power-consumption system, the electromagnetic compatibility performance of the system is enhanced, and the shake of the system structure is reduced.