The invention discloses a method for improving performance of an AlTiSiN coating through low-negative bias high-energy Ar <+> etching cleaning. The method comprises the steps that a multi-arc ion plated vacuum furnace is vacuumized, then, Ar gas is introduced and is heated to 450 DEG C, a cleaning Ti target is started, then, an anode target material is started, the cleaning Ti target and the anodetarget material perform positive-negative traction electron motion, Ar <+> is generated through collision of electrons and the Ar gas, negative bias is controlled to be minus 180 V, and Ar <+> is attracted to perform ion bombardment on the surface of a substrate for 30 min; and the AlTiSiN composite coating is deposited on the treated substrate. According to the method, the substrate is subjectedto etching cleaning through only high-energy Ar ions in the low-negative bias condition, the film-substrate binding force of the AlTiSiN coating can be remarkably improved through the etching cleaning technology, wear and friction resistance and cutting performance of the coating are improved, and the coating is applicable to a harsh high-hardness material high-speed cutting environment, and hasgreat application prospects in the field of cutter and surface protection.