A　random　laser　was　achieved　in　a　polymer　membrane　with　silver　nanoflowers　on　a　flexible　substrate.　The　strong　confinement　of　the　polymer　waveguide　and　the　localized　field　enhancement　of　silver　nanoflowers　were　essential　for　the　low-threshold　random　lasing　action.　The　lasing　wavelength　can　be　tuned　by　bending　the　flexible　substrate.　The　solution　phase　synthesis　of　the　silver　nanoflowers　enables　easy　realization　of　this　type　of　random　lasers.　The　flexible　and　high-efficiency　random　lasers　provide　favorable　factors　for　the　development　of　imaging　and　sensing　devices.