The invention provides a method for preventing a metal fuse from being excessively etched. The method comprises the steps of providing a metal fuse, and depositing an interlayer film on the metal fuse; forming a top metal layer on the interlayer film, wherein titanium nitride layers are respectively arranged on an upper surface and a lower surface of the top metal layer; etching the top metal layer, and forming a bonding pad and a protection pattern arranged above the metal fuse; defining an etching window above the bonding pad and the protection pattern after a passivation layer is deposited;and etching according to the etching window to remove titanium nitride on an upper surface of the bonding pad, leftwards and rightwards opening the windows in the metal fuse to release a product generated by burnout of the metal fuse when a lower-layer fuse is protected by using the protection pattern as a mask. By the method, the metal fuse is protected, the windows are also formed in the metalfuse, the cost is reduced, meanwhile, the metal layer at a lower layer is protected, windows are formed in a left edge and a right edge of the metal fuse, and the product generated by burnout of the metal fuse is conveniently released and is prevented from being gathered in an original place to for short circuit.