The invention relates to a wavelength division multiplex transmission system, comprising a wideband light source, an optical circulator, 2Nx1(de) multiplexer, two wavelength interleaver, N Fabry-Perot laser diode, and N optical receiver, characterized in that the N Fabry-Perot laser diode are connected with odd-number ports of the (de) multiplexers, the N optical receiver are connected with even-number ports of the (de) multiplexers, common ports of the (de) multiplexers are connected with a first port of a first wavelength interleaver, a second port of the first wavelength interleaver is connected with a second port of the optical circulator, a first port of the optical circulator is connected with the wideband light source, a third port of the optical circulator is connected with a second port of the second wavelength interleaver, and a third port of the second wavelength interleaver is connected with a third port of the first wavelength interleaver.