Multi-wavelength　colloidal　quantum　dots　(CQDs)　lasers　are　achieved　using　complex　grating　structures　and　flexible　substrate.　The　structure　contains　graduated　periods　and　rectangular　cavity　fabricated　via　interference　lithography,　which　acts　as　the　distributed　feedback.　A　layer　of　densely　packed　CQDs　film　is　deposited　on　the　cavity　via　spin　coating　technique.　The　performance　of　CQDs　lasers　is　investigated　based　on　different　distributed　feedback　cavities.　Multi-wavelength　lasing　is　achieved　based　on　a　flexible　rectangular　cavity.The　fabricated　multi-wavelength　CQDs　lasers　platform　can　be　used　to　explore　various　applications　and　research　areas　especially　in　the　optical　communication,　mechanical　sensing　technologies　and　in　various　other　fields.　©　2019　The　Author(s).