The invention discloses a double-layer shell 
titanium alloy deflector shroud acoustic three-dimensional control method. The double-layer shell 
titanium alloy deflector shroud acoustic three-dimensional control method comprises the following steps of, firstly, determining the spatial range of an acoustic window according to agreed horizontal scanning angle and 
vertical angle of 
pitch and under thecondition that mold lines are determined; secondly, performing structure optimization on an 
acoustic cavity, specifically, arranging and computing the structure of non-
acoustic transmission areas according to the determined range of the acoustic window; thirdly, performing acoustic modeling calculation according to the material and structure of the acoustic window; fourthly, performing vibration and 
noise reduction design inside the 
acoustic cavity, emphatically controlling the 
noise within the working frequency range of a 
sonar, applying sound absorbing materials and vibration and 
noise reducing materials onto the rear wall of the 
acoustic cavity, a 
sonar mounting platform and a bottom non-
acoustic transmission area. The double-layer shell 
titanium alloy deflector shroud acoustic three-dimensional control method integrates multiple disciplines and combines 
engineering practical experience, thereby being high in systemic performance and 
operability and providing an effective 
engineering method for acoustic control of a 
bulbous bow deflector shroud.