Air filtration materials such as protective masks can protect humans from airborne pathogens; however, most of the existing protective filtration materials are aimed to intercept bacteria. Therefore, in this work, modified polypropylene- (PP-) based melt-blown nonwovens with antibacterial property were prepared for reducing the infection rate during the filtering process. Firstly, an N-halamine precursor, 2,4-diamino-6-diallylamino-1,3,5-triazine (NDAM) monomer, was grafted with PP polymers (PP-g-NDAM) by reactive extrusion method, and the grafting effect was confirmed by nitrogen analysis and FTIR spectra. Then, the obtained PP-g-NDAM was mixed with pristine PP resins in different ratios to prepare the filter materials by melt-blown technology. Finally, the new PP-g-NDAM melt-blown filter materials were finishing treated by the chlorination and electrostatic process, which showed a high filtration efficiency with low pressure drop and a potent antibacterial effect against Escherichia coli (E. coli). This work provides an innovative method for manufacturing antibacterial filtration nonwovens, which can improve the quality of conventional filtration products.