The invention discloses a sludge sintered brick auxiliary and an application method thereof. For overcoming the defects that in the prior art, when sludge addition amount in a green brick material is large, sintered bricks are insufficient in strength and low in yield, the sludge sintered brick auxiliary and the application method thereof are provided. The auxiliary is prepared from, by mass, 25-35% of B2O3, 40-60% of ZnO and 15-25% of MnO2, by means of the auxiliary, in the sintering process, crystalloid in green bricks is enlarged, the pore size is reduced, and the nonuniformity of shrinkage deformation of the green brick material in the high-temperature sintering process is reduced, so that the yield is increased, and the strength of finished brick products is improved. The invention further provides application of the auxiliary to sludge sintered bricks, and the application method includes the step of adding the auxiliary into the green brick material and mixing auxiliary evenly. The sludge sintered brick auxiliary is simple in component and beneficial for stability of chemical reactions in the sintering process, the number of the chemical reactions is small, and the quality of the sludge sintered bricks manufactured through a new sludge sintered brick process realized by adopting the sludge sintered brick auxiliary meets the industrial standard.