Lasers　with　multi-wavelength　colloidal　quantum　dots　(CQDs)　can　be　achieved　using　complex　grating　structures　and　flexible　substrate.　The　structure　contains　graduated　periods　and　rectangular　cavity　fabricated　through　interference　lithography,　which　acts　as　the　distributed　feedback　cavity.　A　layer　of　densely　packed　CQD　film　is　deposited　on　the　cavity　via　spin　coating　technique.　The　performance　of　CQD　lasers　based　on　different　distributed　feedback　cavities　is　investigated.　Multi-wavelength　lasing　is　achieved　based　on　a　flexible　rectangular　cavity.