The present invention provides a die which comprises a die holder, a die core, and an adjusting member. The die holder is provided with a holding groove, the die core is arranged inside of the holding groove, and the adjusting member is arranged inside of the holding groove and is positioned between the die holder and the die core. The die further comprises a block which is arranged on the adjusting member and is adjacent to the die core. The die of the present invention can further comprises two locking pieces, the adjusting member and the die core are fixed with each other by means of one of the locking piece, and the block, adjusting member and the die holder are fixed by means of another locking piece. The die core of the present invention can be disassembled and assembled rapidly, and the die accords with the economic efficacy of manufacturing of products.