The invention relates to a method for accelerating the solid-liquid separation of a nanometer particle suspension, and belongs to the technical field of wastewater treatment. The invention provides the method for accelerating the solid-liquid separation of the nanometer particle suspension for solving the problems that the nanometer particle after a nanometer material is applied to treating wastewater is difficult to settle and therefore the quality of treated water is influenced. An organic polymer flocculant polyacrylamide (PAM with the molecular formula C3xH5xNxOx) is fed into the nanometer particle suspension; under the actions of adsorption bridging, weep flocculation and the like of the PAM, the nanometer particle and the PAM are subjected to mixing and flocculation steps to form a floc which is large in particle size and easy to settle so as to accelerate the settlement of the nanometer particle; solid-liquid separation is achieved under the action of gravity; nanometer particle residue amount in supernatant fluid is reduced; the turbidity of the treated water is significantly reduced; and the quality of the treated water is ensured. The separation method provided by the invention is simple in operation, low in cost, and suitable for the solid-liquid separation of the nanometer particle containing suspension, such as the suspension generated when the nanometer material is applied to treating water pollution.