Marine dredged slurry generally features fine particles，high moisture content，and poor permeability. The flocculant vacuum preloading method can increase the reinforcement effect of marine dredging significantly. However，at present，the flocculation and consolidation characteristics of marine dredged slurry in Bohai Bay are unclear. This paper investigates the flocculation and consolidation characteristics of marine dredged slurry after pre-treatment with CaO and APAM based on the mineral composition and physical properties of the Dongying reclamation soil. The results show that the dredged slurry in the area is silty and clay，with quartz and calcium carbonate as the primary mineral components and some clay minerals such as muscovite and chlorite. The flocculation rate is speedy after adding organic flocculant APAM with an amount between 100 and 300 g/m3. It only takes about 5 minutes to complete the solid-liquid separation and discharge an extensive amount of supernatant. The volume of the final supernatant increases by 1/4-1/3 compared with that without flocculant. The addition of inorganic flocculant CaO also speeds up solid-liquid separation. However，the volume of supernatant is less than that without adding flocculant，which differs entirely from the organic flocculant. The consolidation coefficient of the dredged slurry will increase to different degrees after adding flocculants：The consolidation coefficient rises as the organic flocculants are constantly added to the dredged slurry. However，the inorganic flocculants are different：The consolidation coefficient increases first and then decreases with the increase in the added amount. The optimal added amount should be adopted to get the best consolidation effect. The research results are of great theoretical significance for vacuum preloading treatment of marine dredged slurry in Bohai Bay.