In order to get higher noise reduction of the silencer, the computational fluid dynamics (CFD) and the computational aeroacoustics (CAA) are selected for numerical simulation. Under the working condition of firing 9 mm× 19 mm pistol cartridge, the number and inclination angle of the silencer bowls are selected as the research variables. The inner and the outer flow field of the silencer, and the information of the fluid pressure on the integrated surface of the sound source are obtained by large eddy simulation (LES) numerical calculation method, and then the acoustic information on the integrated surface of the sound source, and the sound pressure signal of the measuring points of the far filed can be calculated according to the acoustic wave equation. Finally, the overall sound pressure level (OSPL) of jet noise at different specified measuring points is obtained. The analysis shows that the silencer bowl with 60° inclination has the lowest OSPL at all measuring points, and when the change in the number of silencer bowls causes the adjacent bowls and the bullet to form the maximum confined chamber, the lowest overall sound pressure level can be got at all measuring points.