Abstract: An approximate method is brought forward to predict the acoustic pressure based on the surface velocity. It is named Element Radiation Superposition Method.The study finds that each element in ATV equals the acoustic pressure radiated by the corresponding surface element vibrating in unit velocity and other surface elements keep still, that is the acoustic pressure radiated by the corresponding baffled piston vibrating in unit velocity.So,it utilizes the acoustic pressure radiated by a baffled piston to establish the transfer relationship between the surface velocity and the acoustic pressure.The total acoustic pressure is obtained through summing up the product of the surface velocity and the transfer relationship.It adopts regular baffles to fit the actual baffle in order to calculate the acoustic pressure radiated by a baffled piston in calculating.This approximate method has a large advantage in calculating speed and memory space relative to Boundary Element Method.Numerical simulations show that this approximate method is reasonable and feasible.