A protein skimmer comprises a body (1) and a waste liquid recycling device (2). A water inlet pipe (3) and an air inlet pipe (4) are arranged on the body (1) and a foam generating device (5) is provided in the body. The foam generating device (5) comprises a foam generating plate (6) provided with air holes. A water pump (7) is disposed above the foam generating plate (6), and drives a needle brush (8) below the foam generating plate (6) to rotate by a rotary shaft passing through the foam generating plate (6). The needle brush (8) is provided with a ventilating structure and an air inlet cylinder (9) connected with the air inlet pipe (3) on one side is connected to the bottom of the needle brush (8). By changing the positions and the structures of the water pump and the needle brush, a foam producing region is expanded and the air inlet is more efficient. The protein skimmer with a smaller size can realize a same filtering effect thus the production cost and consumed plastic raw materials are saved and the air inlet efficiency and the foam producing efficiency are improved by 30-50% respectively. The water pump whose flux and power are lower than those of the existing water pump by 30-50% respectively can be used thus the purchasing cost and the production cost are saved.Linvention concerne un écumeur de protéine comprenant un corps (1) et un dispositif de recyclage de déchets liquides (2). Un tuyau dentrée deau (3) et un tuyau dentrée dair (4) sont disposés sur le corps (1) et un dispositif de génération de mousse (5) est disposé dans le corps. Le dispositif de génération de mousse (5) comprend une plaque (6) de génération de mousse pourvue dorifices dair. Une pompe à eau (7) est disposée au-dessus de la plaque (6) de génération de mousse, et amène une brosse daiguille (8) sous la plaque (6) de génération de mousse à tourner au moyen dun arbre rotatif passant à travers la plaque (6) de génération de mousse. La brosse daiguille (8) comprend une structure de ventila
