Cladding powder, zinc-aluminum-magnesium coated steel plate weld bead anticorrosive coating and preparation method thereof

The invention relates to cladding powder, a zinc-aluminum-magnesium coating steel plate weld bead anticorrosive coating and a preparation method of the zinc-aluminum-magnesium coating steel plate weld bead anticorrosive coating, the cladding powder comprises basic metal powder, and the chemical components of the basic metal powder comprise zinc, aluminum and magnesium; wherein in percentage by mass, the content of the aluminum is 4 to 20 percent, and the content of the magnesium is 2 to 10 percent. Chemical components of the cladding powder are designed; the content of aluminum is controlled, an iron-aluminum phase is formed with a weld joint matrix, the binding force of a weld joint anti-corrosion layer and a weld joint is improved, a formed corrosion product can keep the alkaline environment of the surface of the weld joint anti-corrosion layer, and meanwhile the hardness of aluminum oxide on the surface of the anti-corrosion layer is provided; the content of magnesium is controlled, and hard-phase Mg-Zn an