Abstract: A method and an apparatus or pressing groove section with a bending angle smaller than or equal to 90 degrees are provided. The apparatus comprises an upper convex die and a lower concave die are used for processing. The convex die comprises an expansion sleeve and an expansion core which are nested with each other. At least one of a central hole of the sleeve body and the core body is a wedge with a larger top and a smaller bottom, and a relative locking mechanism is arranged between the core body and the core body. The concave die comprises a multi-petal-shaped inner concave die and an external outer concave die which are in elastic connection.