The invention provides a flexible quantum dot random laser based on a PDMS polymer. The flexible quantum dot random laser comprises two PDMS film layers and a permeation layer sandwiched between two PDMS film layers. The concentration of cross-linking agents in the PDMS film layers is larger than 4%. The concentration of a cross-linking agent in the permeation layer is 2% to 4%. The permeation layer is a PDMS film layer with uneven internal stress distribution and is provided with at least one group of linear grooves that diverge from a center point to each direction or at least one group of annular grooves which gradually diffuse from the center point, and quantum dots penetrate the grooves. The quantum dots play roles of gain mediums during a random laser emission process, by using the uneven internal stress distribution of the permeation layer, localized refractive index inconsistency is formed through a photoelastic effect, multiple scattering effects are enhanced, and a purpose ofreducing an existing random laser threshold is achieved. The quantum dots are filled in the permeation layer with low concentration, and the film of the invention has the characteristic of long-termoperation compared with a quantum dot film on the surface of a glass substrate. At the same time, since the PDMS is a flexible material, the PDMS has a flexible characteristic, and the preparation ofthe flexible random laser can be achieved.