Abstract: Based on TSMC 0.18μm CMOS process, a high conversion efficiency energy harvesting circuit with dual-input and dual-outputwas designed for wireless sensor nodes of the Internet of Things (IoT).With the support of maximum power point tracking technology and rectification technology, the autonomously harvest energy from both piezoelectric energy (PZ) and thermoelectric energy (TEG) sources was realized. Under light load, the Boost circuit can supply power to the super-capacitor and the load to achieve dual output, and under heavy load, the Boost and Buck circuits supply power to the load at the same time to compensate for the energy shortage. By introducing the independent switching technology of discontinuous conduction mode (DCM) and continuous conduction mode (CCM), the reverse current leakage on the inductor is effectively reduced and the conversion efficiency of the circuit is significantly improved. The simulation results show that the peak conversion efficiency can reach 90.6%.