Radar electronic rearview mirror system for bicycles

A radar electronic rearview mirror system for bicycles is provided with an environment sensing module, a display module, and a light sensing module. The environment sensing module is disposed at a rear of the bicycle and captures environmental information from a rear side of the bicycle, outputting an environment sensing signal. The display module is disposed at a front of the bicycle and is electrically connected to the environment sensing module to receive the environment sensing signal. The display module has a screen that displays an image corresponding to the environment sensing signal. The light sensing module is disposed at the front of the bicycle and is electrically connected to the environment sensing module and/or the display module. The environment sensing module and/or the display module is operable in a normal mode or a night mode according to the light intensity sensing signal output by the light sensing module.