The invention discloses an under-coal-mine multi-wavelength wireless optical relay emergency communication system which comprises a main control node and a plurality of relay nodes. The main control node and each relay node are connected into a linear link structure, the control node is in a communication with each relay node by the aid of red lasers, one relay node is in a communication with the other relay node by the aid of red lasers, and each relay node is in a communication with a mobile station through ultraviolet light. The invention discloses an under-coal-mine multi-wavelength wireless optical relay emergency communication method which particularly includes the steps: building a wireless light relay communication link; transmitting data according to the built communication link; disassembling the built wireless light relay communication link. According to the communication system, the red lasers and the ultraviolet light serve as information transmission carriers, existing communication types are effectively supplemented, the communication system is high in anti-jamming capability and can effectively meet communication requirements in mine emergency rescuing scenes, and point discharge is not easily generated.