In order to simplify the transmitter structure of the multi-wavelength optical packets switching system, a method of multi-wavelength optical packets generation based on Mach-Zehnder delay interferometer (MZDI) is proposed. Only one MZDI is used to transform the payload format from wavelength division multiplexing (WDM) differential phase shift keying (DPSK) to WDM duobinary- carrier- suppressed- return- to- zero (DCS- RZ), meanwhile, couple the WDM non-return-to-zero (NRZ) label with the WDM payload and produce the WDM DCSRZ optical packets at the output of MZDI. A simulation of 4 × 40 Gb/s DCS- RZ optical packets is generated, transmitted into fiber and then separated into the label and payload. Detection is performed to verify the feasibility of this method. The simulation results show that after 240 km fiber transmission, the power penalty of the payload after the separation using Fabry-Perot (F-P) filter is only 1.8 dB.