The invention discloses a fine sand screening device. The fine sand screening device comprises a box body, an impacting mechanism and a screening mechanism; the impacting mechanism is arranged in thebox body, and the impacting mechanism comprises a scattering disc and impacting teeth; tooth plates with circumferential distribution are perpendicularly and fixedly connected to the upper end surfaceof the scattering disc, a center shaft is fixed to the scattering disc in a sleeving mode, and the impacting teeth with circumferential distribution are uniformly distributed at the positions, located on the inner wall of the outer side of the scattering disc, of the box body; and the screening mechanism comprises a collection cover and a screening cover, the screening cover is arranged below thecollection cover, the screening cover is fixedly connected with a spiral screen plate in a spiral rising shape, and a slag collecting groove is formed below the screening cover. Sand blocks and the impacting teeth are impacted and crushed by arranging the scattering disc and the impacting teeth, and subsequent screening is facilitated; and the tapered screening cover and the spiral screen plate in a spiral rising shape are arranged to enable sand material comprising waste slag to roll in a spiral waste slag channel, sufficient screening is achieved, the removal rate of the waste slag is improved, the screening out rate of fine sand is improved, and thus, the screening effect is improved.