The present invention discloses a method for achieving Si waveguide single scattering based on a gradient phase of an individual particle. The objective of the invention is to solve problems that current Si waveguide single scattering depends on interference among a plurality of structures and direction switching of scattering cannot be achieved. The method provided by the invention employs a spinning-track interaction of an individual particle to generate a gradient phase with chiral correction of symbols (+/-) and incident light in a waveguide propagation direction, the effect is equivalentto that a transversely propagated wave vector is provided to normally incident circularly polarized light to achieve single scattering, the chirality of the incident light is changed to achieve switching of different scattering directions, and therefore, dependence on interference among the plurality of structures is avoided, and the work bandwidth, the robustness and the flexibility of the systemare greatly improved.