Metal polishing solution and preparation method and application thereof

The invention discloses a metal polishing solution and a preparation method and application thereof. The preparation method comprises the steps that a first aluminum oxide precursor serves as a raw material and is calcined, the calcined material is subjected to wet ball milling, and the solid content of ball milling slurry is 30-55% till the particle size D is 0.8-4 m; wet ball milling is carried out on a second aluminum oxide precursor until the solid content of the ball milling slurry is 30-70% until the particle size D is 3-6 m; and the ball milling slurry obtained through calcination after-treatment, the ball milling slurry obtained through direct ball milling of the precursor, a surfactant, a defoaming agent, a corrosion inhibitor and a pH value regulator are mixed, and the metal polishing solution is prepared. According to the metal polishing solution, the prepared metal polishing solution can still have excellent suspension stability under the condition that a commercially available suspension stabiliz