The invention discloses a method for quickly synthesizing full-spectrum perovskite quantum dots through organic-inorganic auxiliary ion exchange. According to the method disclosed by the invention, full-spectrum perovskite quantum dots with multiple colours are obtained by taking green inorganic perovskite quantum dots CsPbBr3 solution as mother liquid, injecting the CsPbBr3 solution, organic polymer solution and inorganic salt solution into a multi-channel micro-reactor, and performing a reaction in a flowing process in micro-flow channels of the multi-channel micro-reactor. The quantum dotssynthesized by the method disclosed by the invention are high in stability; raw materials are cheap; the operation is convenient; industrial large-scale production is benefited.