The utility model relates to a blank positioning device used for an extrusion die, comprising an upper die, a lower die and a top plunger arranged in the lower die, wherein, a compression spring and a positioning bush are sequentially sheathed onto a small-head of an upper end of a top plunger column. The upper end of the positioning bush clings to a step of the lower end of a die inlet of the lower die and the lower end clings to the compression spring. The upper end of the positioning bush is sheathed to a small-head outer column face of the lower end of the blank. An inner circle face of the positioning bush respectively is matched with the small-head column face of the upper end of the top plunger column and the small-head column face of the lower end of the blank at intervals. The device mainly has the advantages that the positioning bush and the compression spring are additionally arranged on the top plunger column so as to solve the machining positioning and unstable extrusion of positive-extrusion blanks. The blank positioning device has simple structure, reliable positioning capability, strong practicability and low cost.