The acoustic lens is used to focus the acoustic energy to realize narrow beam acoustic radiation of small size transducer in this paper. The simulation models of single concave acoustic lens and double concave acoustic lens are established respectively by finite element method. The structural parameters of acoustic lens have been optimized. The double concave acoustic lens directional transducer is designed and fabricated, and the performance of the prototype of the transducer and the acoustic lens are tested in the anechoic tank. The radiation area diameter of the transducer prototype is 120 mm. After setting the acoustic lens, the transmission voltage response level is increased by 4 dB. The -3 dB beam-width is changed from 76° to about 30°(@ 10 kHz),which conforms to the simulation results. The experimental results show that the acoustic lens effectively reduces the beam width of the transducer and improves the transmitting voltage response of the main beam of the transducer, which verifies the effect of the double concave acoustic lens on optimizing the directivity of the transducer.