The invention discloses a powdery flocculant. The powdery flocculant is prepared from the following raw materials in parts by weight: 2-6 parts of polyvinylpyrrolidone, 4-9 parts of carbon sodium, 3-7parts of maleic acid monohexadecane sodium salt, 5-9 parts of sodium carboxymethylcellulose, 2-7 parts of polyphosphorus ferric chloride, 4-8 parts of a polysilicic acid solution, 3-8 parts of aluminum sulfate, 4-8 parts of carboxymethyl chitosan, 3-8 parts of polyaluminum chloride, 4-9 parts of sodium aluminum sulfate, 3-8 parts of dimethyl diallyl ammonium chloride and 2-6 parts of tetraethylenepentamine. The powdery flocculant has the advantages of wide raw material source, low production cost, small feeding amount, good flocculation excitation effect, low flocculation treatment cost and the like.