The invention discloses a core pulling mechanism of a mechanical locking oil cylinder of an injection mold, which is provided with a locking mechanism comprising a locking block (28), a locking block slideway (26) and a locking oil cylinder (27). When the mold is closed for injection molding, an insert block slideway (23) of the core pulling mechanism of the oil cylinder can be locked for preventing the retreating, thereby avoiding the defects of flashings, burrs and the like of a product and improving the appearance quality of the injection molded product. The insert block slideway (23) and an auxiliary slideway (25) of the core pulling mechanism are obliquely arranged, the core pulling mechanism can be applied to the situations that the shape fluctuation in the back-off position of the appearance of the product is greater and the core pulling direction has a slope with the plane, and the core pulling can be realized for the product in the complex shape.