Dense dewatering of tailings is a key link in the tailings filling process. In order to explore the dense dewatering performance of tailings in a mine, static and dynamic flocculation sedimentation tests of tailings were carried out on the basis of the basic physicochemical properties of tailings. A static flocculation sedimentation test was designed with the mass concentration of tailings slurry, the type of flocculant added and the amount of flocculant added as the influencing factors and the sedimentation rate as the research index. The dynamic flocculation sedimentation test with feed speed, feed mass concentration and flocculant content as influencing factors, and solid content in overflow water, underflow mass concentration and settling velocity of tailings as research indexes, and based on RSM analysis method, revealed the dynamic flocculation settlement law of total tailings under the interaction of multiple factors. The results showed as follows: 1) Through the static flocculation sedimentation test, the optimal flocculating dosage was CKFA02#, the optimal addition amount of flocculant was 20g/t, and the optimal feed concentration of tailings slurry was 10%~12.5%; 2) According to the response surface model established by dynamic flocculation settlement test, the biggest factor affecting underflow mass concentration and solid content in overflow water is slurry feeding speed, and the biggest factor affecting tailings settling speed is slurry feeding mass concentration. The interaction between slurry feeding speed and feed mass concentration has the biggest influence on underflow mass concentration. Slurry feed rate and flocculant add amount have the greatest influence on the solid content of overflow water, slurry feed rate and flocculant add amount have the greatest influence on the settling rate of tailings. 3) The optimal settlement parameters are the feed rate of tail mortar 0.55t /m2·h, feed mass concentration 11.12%, flocculant addition amount 30.0g/t. Under the optimal flocculation settlement parameters, the underflow mass concentration is 60.6%, the solid content of overflow water is 251.4mg/L, and the settlement rate of tail sand is 58.06mm/s.