The theoretical study of the double laminated composite bending transducer with fixed boundary conditions has been carried out by Rayleigh method. The radiated sound pressure of double laminated composite bending vibration transducer and its directional expression are deduced using the principle of superposition field based on the deduction of the resonance frequency and displacement distribution function. The influence of the strcutural parameters of the composite transducer on the direction is analyzed by the numerical calculation and compared with the corresponding piston plate. The results show that the structural parameters of the composite bending transducer have different effects on the acoustic field. When the other parameters are given, the characteristics of sound field directivity are no side lobe, large flap angle, sound pressure with short acting distance and the angle of the directional angle becomes smaller with the increase of the frequency.