Blanking method for stamping and shearing without edge collapse

The invention discloses a blanking method for stamping and shearing without edge collapse. Comprising the following steps: S1, extrusion: flatly placing a workpiece in a die, determining the width of a part needing to be punched as L, then extruding the edge of the part needing to be punched by adopting a convex tip, extruding the upper and lower end faces of the workpiece by adopting the tip in a vertically symmetrical manner, and after the upper and lower peripheries of the workpiece are extruded, performing extrusion on the upper and lower end faces of the workpiece; the thickness t of the extruded part is larger than that of other parts, a convex edge is formed, and a deep groove is formed in the edge of the part needing to be punched, so that a pre-cutting surface is formed. S2, flattening; and S3, trimming and blanking. According to the method, in the step S1, before shearing and blanking, a material on a shearing surface is extruded to be convex, a pre-cutting surface is formed on a shearing section, t