A solar speaker self-adjusting control system includes a photovoltaic panel, a voltage conversion device, a speaker device, an embedded processing device, and a calling device. The photovoltaic panel is for receiving solar energy and outputting a voltage signal; the voltage conversion device is connected to the photovoltaic panel for converting the voltage signal outputted by the photovoltaic panel into voltage values required by the system; the embedded processing device is connected to the calling device and speaker device for converting a voice signal transmitted from the calling device into a control current that drives the operation of the speaker device; and the calling device is embedded into a dashboard at a front end of the motor vehicle and connected to the embedded processing device installed in the dashboard at the front end of the motor vehicle through a cable. This system achieves the self-adjusting control effect of a solar speaker.