The invention discloses an emission reduction method for sintering flue gas PM2.5 based on adsorption by a reinforced material layer. The method comprises the following steps: slaked lime is added into an iron ore sintering raw material in a pellet preparation process at a position 4.5-5m away from a discharging end of a second cylinder drum type mixer tail part, an adsorbent solution is sprayed at a position 3-3.5m away from the discharging end, in order to obtain pellets whose surfaces are adhered by calcium hydroxide and the adsorbent, and the adsorbent and slaked lime are used for absorbing and bonding PM2.5 and discharging of PM2.5 in the sintering process is reduced. A semi-dry process or a dry method desulphurization-bag dedusting technology is used for cleaning flue gas at a sintering and heating segment after cyclone dust removal, flue gas at a non-heating segment is cleaned by electric precipitation, so that concentration of PM2.5 in the discharged flue gas is reduced to 20mg/Nm<3> or below, strict discharge standard requirements are satisfied, original sintering flows are not changed, large-scale purifying equipment are not additionally installed, and high efficient economic treatment of sintering flue gas PM2.5 is realized.