Current photovoltaic (PV) maximum power point tracking (MPPT) technology has the following shortcomings: it is easy for the system to fall into a local power peak under the working condition of partial shadow; it is easy for the system to oscillate and even be unstable when the load fluctuates. In order to solve these problems, an adaptive design scheme of PV global MPPT technology is proposed. The scheme combines a PV output voltage scanning circuit and a Zeta chopper circuit organically. Through the simple circuit topology of single switch tube, not only can the voltage power characteristic of photovoltaic output terminal be quickly scanned and the position of global maximum power point can be located, but also, according to the needs of the post-circuit, the DC regulation of voltage buck or boost chopping can be realized. After a sudden change of irradiance or load, the system can adjust the duty cycle of the switch tube adaptively to ensure stable operation near the global maximum power point and avoid large oscillation and instability. Through PSCAD-EMTCD simulation and a prototype test, the results show that the scheme can track and lock the current PV global maximum power point adaptively and quickly under various complex conditions including partial shadow. This work is supported by the Intercollegiate Key Project of Nature Science of Anhui Province (No. KJ2019A1244, No. KJ2019A1245, and No. KJ2020A0928), the Outstanding Young Talents in Colleges and Universities of Anhui Province (No. gxyq2019202) and the Program for Special Support of Top-Notch Professionals of Anhui Province (No. gxbjZD59).