The present invention relates to a total-reflection-type rain sensor using a mirror, which is attached to the glass of a vehicle to detect raindrops falling onto the glass of the vehicle, and which outputs a signal capable of controlling the speed and the cycle of the vehicle wipers according to the amount and falling frequency of the detected raindrops. In more detail, the total-reflection-type rain sensor using a mirror according to the present invention is a rain sensor that is technically characterized by including: a light emitting unit; an adhering unit; a light receiving unit; and a controller, is attached to the glass of a vehicle, and detects raindrops falling onto the glass of the vehicle, wherein the light receiving unit receives light that is emitted from the light emitting unit to be incident on the glass of the vehicle and is totally reflected from the glass of the vehicle, a signal with respect to the amount of received light is output, the controller communicates with the vehicle, a threshold value that can operate the wipers of the vehicle is pre-stored, the signal from the light receiving unit is received to analyze the amount of raindrops corresponding to the amount of light, and when the amount of raindrops exceeds the threshold value, the wipers are operated.