The invention provides a preparation method of recycled aggregate for inhibiting an alkali-aggregate reaction. The preparation method is prepared from the following steps (1) the recycled aggregate iscollected, specifically, recycled concrete is crushed and sieved, and thus the recycled aggregate with the concrete required size is prepared; (2) silica fume slurry is prepared, specifically, according to the water-solid mass ratio of 5:1 to 15:1, silica fume is dissolved in water, and the silica fume slurry is prepared; (3) the silica fume slurry is subjected to vacuum suction to prepare the recycled aggregate, specifically, the collected and prepared recycled aggregate and the silica fume slurry are jointly placed into a vacuum container with the negative pressure for 6-18 h, and it is ensured that the silica fume slurry is fully sucked into recycled aggregate attached slurry body; and (4) the recycled aggregate with the sucked silica fume is dried, specifically, the recycled aggregatesubjected to vacuum sucking of the silica fume slurry is dried, and thus the recycled aggregate for effectively inhibiting alkali activity is obtained. According to the preparation method, a technology is simple, the cost is low, meanwhile, the recycled aggregate with the alkali activity can be efficiently utilized, and the environmental pressure is relieved.