In this paper, we describe the research and development of the maximum power point tracker (MPPT) for a photovoltaic module array (PVMA) under different sunlight intensities and temperatures. In this study, an improved power feedback method (IPFM) is used to track the maximum power point (MPP) of the PVMA. Because a traditional power feedback method (PFM) is used for maximum power tracking, once the sunlight intensity and temperature change, the MPP of the PVMA changes accordingly. Nevertheless, the fixed duty cycle variation of the boost converter is used for the tracking step in the traditional PFM, so that it may take a long time to track to the MPP. For this reason, an MPPT based on the IPFM is proposed in this paper, so that its tracking step is adjusted adaptively according to the slope of the power-voltage (P–V) characteristic curve of the PVMA. Moreover, the initial voltage for starting tracking is set to 0.8-fold the MPP voltage Vmp of the PVMA under standard test conditions (STCs). First, a programmable DC power supply (62050H-600S) produced by Chroma ATE Inc. is used in this study to simulate the output characteristics of a 4-series and 1-parallel PVMA, and then simple voltage and current sensors are used to feed back the voltage and current of the PVMA, followed by MPP tracking by the IPFM. From the experimental results, it is proved that the proposed IPFM yields a better tracking speed response and steady-state performance than the traditional PFM under different working environments.