PROBLEM TO BE SOLVED: To provide an optical signal transmission device which carries out pre-equalization of XPM by an optical transmission line.SOLUTION: An optical signal transmission device transmits a wavelength division multiplex optical signal having at least two wavelength channels. The optical signal transmission device has an optical signal transmitter which transmits a polarization multiplexed optical signal for each wavelength channel. In the optical signal transmission device, the optical transmitter of each channel includes: a first calculation unit which calculates wavelength information of the optical transmitter on the basis of information of an optical transmission line including a plurality of spans and a transmission signal which is a polarization multiplexed signal, and transmits the wavelength information of the optical signal transmitter to the optical signal transmitters of the other channels; and a second calculation unit which receives the wavelength information of the optical signal transmitters of the other channels, and pre-equalizes XPM in the optical transmission line of the transmission signal on the basis of the wavelength information of the optical signal transmitters of the other channels.