The invention discloses a multi-
wavelength single-
fiber bidirectional optical 
transceiver module and a working method thereof. The multi-
wavelength single-
fiber bidirectional optical 
transceiver module comprises a transmitting end, a receiving end, a common end, and an optical 
transceiver assembly, wherein the transmitting end comprises a 
laser group, a collimation lens group and a 
wavelength division 
multiplexing optical 
assembly; the receiving end comprises a 
photodiode group, a convergence lens group and a wavelength division de-
multiplexing optical 
assembly; the common end is the input / output port of an optical 
signal; the 
wavelength division multiplexing optical assembly comprises a first total-reflection mirror, a second total-reflection mirror, a first 
wavelength division multiplexing diaphragm and a second 
wavelength division multiplexing diaphragm; a wavelength division de-
multiplexing optical assembly comprises an optical substrate, a first filter, a second filter, a third filter and a fourth filter; and the optical transceiver assembly comprises a first polarization light splitter, a 
magnetic rotation optical sheet, a 22.5-degree 1 / 2 wave plate, a first wave plate, a second polarization light splitter, a second wave plate, and a third polarization light splitter. According to the multi-wavelength single-
fiber bidirectional 
optical module, input and output of multi-wavelength optical signals on the same fiber can be carried out, the size and the cost of the optical transceiver are reduced, the wavelength multiplexing diaphragm is easy to coat, the performance is better, and the cost is low.