A multi-needle assembly for cosmetic procedure includes a main body having an inner space extending from one to the other ends, a reciprocating member provided in the main body to be moved along an inner circumferential surface of the main body in a forward and backward direction, a needle member placed into the reciprocating member 4 and coupled therein, and having a plurality of needles that enter or exit through one end of the main body, a guide suction into or from which the plurality of needles enter or exit, in which the guide suction comprises an opening to be brought into contact with a skin and forms a suction force for sucking in foreign matter from inside while the opening is in close contact with the skin, and a length adjusting means for moving the reciprocating member in a forward and backward direction along a spiral groove and a slide groove formed in the inner circumferential surface of the main body to adjust a projecting length of the needles. Accordingly, the length of the reciprocating member can be adjusted by forward and reverse rotation and advancing and retreating movement in the main body, and there is an effect that the projecting depth of the needles can be accurately and precisely adjusted by setting the position of the needle member coupled thereto.
