Abstract: In view of the unclear attenuation law of shock wave in curved tunnel is unclear, the influence of radius and turning angle on shock wave propagation in curved tunnel is analyzed. It was found that its influence on the wave dissipation efficiency was limited, and the wave dissipation efficiency of curved tunnel is similar to that of direct turning tunnel with the same angle, which is basically less than 7.2%. In order to improve the attenuation efficiency of shock wave in curved tunnel, a new protective idea of constructing arc-shaped diffusion tunnels based on arc-shaped tunnels by setting up diffusion chambers was proposed. The influence laws of diffusion ratio and diffusion forms (inner diffusion, two side diffusion and outer diffusion) on the wave dissipation efficiency of curved diffusion tunnels were also discussed. The calculation shows that curved diffusion tunnel can greatly improve the attenuation efficiency of shock wave, and the attenuation rate can reach 55.9%. Among them, the outer diffusion curved tunnel has the highest wave dissipation efficiency, followed by the inner diffusion type and the double-sided diffusion type. Moreover, the wave attenuation efficiency increases continuously with the increase of the diffusion ratio. As the peak pressure of the shock wave increases, the wave attenuation efficiency of the curved diffusion tunnel also improves, reaching up to 64.4%. When the peak pressure continues to increase, the wave attenuation efficiency of the curved diffusion tunnel slightly decreases but remains basically unchanged. The wave attenuation efficiency of the curved diffusion tunnel decreases with the increase of the positive pressure duration of the shock wave. When the positive pressure duration is 100 ms, the wave attenuation efficiency drops to 25.4%. However, as the positive pressure duration further increases, the wave attenuation efficiency of the curved diffusion tunnel remains almost unchanged.