Discrete acoustic array arranged in a certain geometric structure takes advantages of energy concentration, adjustable radiation direction, and flexible configuration. An array design and optimization method is proposed to solve the difficulty of controlling orientation direction and backward radiation suppression when the acoustic array radiates high-intensity low-frequency sound waves. Firstly, the horizontally arranged linear array is used to limit the width of the main beam, and the design principle of directivity is analyzed. Then, the vertical position and phase of the multi-layer linear array are controlled, thereby achieving the suppression of backward radiation. Finally, an improved genetic simulated annealing algorithm is proposed to optimize the lateral coordinate of the array element and further improve the performance of the array. Simulation and sound field test results show that the design method can effectively control the directivity and backward radiation level of the array. The test results are consistent with the theoretical analysis. When the designed depth array emits 100 Hz sound waves, the half-power angle is 21. 91°. The average radiation suppression ratio in the direction from 50° to 60° is 8. 82 dB and the radiation suppression ratio in the direction from 90° to 180° exceeds 20 dB.