The superplasticity of LY12 alloy was reviewed in this paper. Complex component was extruded by taking advantage of the superplasticity of supplied LY12 alloy. The research demonstrates that in isothermal compression process dynamic recrystallization may occur in supplied LY12 alloy. In superplastic forming test grain refinement was combined with initial extrusion step utilizing dynamic recrystallization to complete grain refinement, which ensured the superplasticity in supplied LY12. In the early stage of extrusion, using high deformation speed and large amount of deformation can result in grain refinement, which primarily satisfied the demand of the superplasticity. In the final stage, the forming speed decreased sharply so that the optimum strain rate was satisfied and the complicated component can be extruded successfully. The resulted product has reasonable flowing traces, which improves its service performance.