The boundary element method is used to calculate the acoustic radiated field of a complicated conformal array of underwater acoustic projecting transducers. At first, the fundamental theory of the boundary element method is carefully studied. The commercial software Pro/ENGINEER and ANSYS is then used to build the boundary element model of the conformal array, and SYSNOISE is used to calculate the acoustic radiated field and the radiation impedance of the array. The technique presented in this paper can be used to predict the performance of projecting transducer array at the stage of preliminary design