The paper builds a physical generalized model of launching type ship lift with scale of 1:20 to study bottom type of ship chamber systematically.The effect of different bottom types on water level fluctuation in chamber tank,adsorption force,slamming force and additional hydraulic load during the ship chamber in and out of water is discussed.The result shows that increasing the angle of sphenoid type at bottom of ship chamber can decrease adsorption force and slamming force effectively.Because the increase of angle of sphenoid increases the mass of the ship chamber,the recommended angle is 4°.