The invention relates to the technical field of sewage treatment, and discloses a sewage treatment flocculation device based on a biofilm process treatment technology, the sewage treatment flocculation device comprises a mixing cylinder, the mixing device comprises a piston block, a first fixed block, a first rotating cover, a second fixed block, a second rotating cover and a promoting device, the piston block is slidably connected to the interior of the mixing cylinder, and the piston block is slidably connected to the interior of the mixing cylinder. A first fixing block is fixedly connected to the piston block, a first rotating cover is rotatably connected to the outer side of the first fixing block, and a second fixing block is fixedly connected to the inner bottom side wall of the mixing cylinder. According to the sewage treatment flocculation device based on the biofilm process treatment technology, through the cooperative action of a second motor, a rotating disc, a connecting rod, a sliding block, a track plate, a track shell, a moving rod, a piston block, a first rotating cover, a second rotating cover, a mixing cylinder, a first motor, a screw rod, a filter cylinder and a rotating fan, the purpose of accelerated mixing of a flocculating agent and water is achieved; therefore, the problem of low flocculation effect is solved.