The invention discloses a method for preparing abalone harslet polysaccharide powder for removing proteins and heavy metals. The method comprises the following steps: preparing an abalone harslet polysaccharide crude solution, performing enzymolysis, performing low-temperature treatment, performing plate and frame filtration, performing ethanol treatment, performing resin adsorption and performing vacuum freeze drying. According to the method disclosed by the invention, the aim of removing proteins and heavy metals can be achieved during preparation of the abalone harslet polysaccharide, the protein removal rate is more than or equal to 90 percent, the removal rates of heavy metals such as arsenic, cadmium, lead and nickel are respectively more than or equal to 94 percent, more than or equal to 98 percent, more than or equal to 88 percent and more than or equal to 90 percent, the finally obtained abalone harslet polysaccharide powder has high purity, protein content of less than or equal to 10 percent and moisture content of less than or equal to 5 percent, and the safety of the product can be fully guaranteed. In addition, temperature in the whole preparation process does not exceed 80 DEG C, the activity of the polysaccharide can be remained to the greatest degree, and the method is simple, easy to operate, low in equipment requirement, low in cost and suitable for industrial application.