An optical communication device includes: a first multiplexer including a first transmitting port and a second transmitting port; a downstream wavelength analyzer configured to analyze first transmission light to recognize a first downstream wavelength corresponding to the first transmission light and analyze second transmission light to recognize a second downstream wavelength corresponding to the second transmission light; and a controller configured to generate a first control signal for allowing the first transmitting port to pass light corresponding to the first downstream wavelength and allowing the second transmitting port to pass light corresponding to the second downstream wavelength, and output the first control signal to the first multiplexer, wherein the first multiplexer, according to the first control signal, controls the first transmitting port to correspond to the first downstream wavelength and controls the second transmitting port to correspond to the second downstream wavelength.