A high-performance waterproof LED decorative lamp, having an inner hollow lampshade, a light-emitting component built in the lampshade, and a lamp holder connected with the lampshade; one end of the lampshade protrudes to form a bayonet connected with the lamp holder, the bayonet is internally plugged with a waterproof plug, the light-emitting component is embedded in the waterproof plug, the waterproof plug is provided with an open cavity, a conductive pin is provided in the cavity, the conductive pin is electrically connected to the light-emitting component and exposed to the bottom of the bottom surface, the side of the waterproof plug is provided with a notch, and the light-emitting component is electrically connected to the inner wall of the lamp holder through the notch.