Abstract: When a strong shock wave interacts with obstacles in a tube, some complex physical phenomena, such as shock wave reflection and diffraction etc., may occur, which generates expansive waves and many other complex wave structures. Previous research has shown that, if the shape of the obstacle is appropriate, the intensity of the shock wave may be attenuated. However, the relationship between the attenuation magnitude of shock waves and obstacles requires further clarification. In this study, numerical investigation of the interaction of shock waves with three triangular obstacles of different slopes of windward sides were carried out using high order numerical schemes, i.e. the immersed boundary method (IBM) and the adaptive mesh refinement (AMR) technology. Results show that, obstacles with a negative windward side slope have the most favourable effects on shock wave attenuation when compared to those with positive and zero slopes. In addition, triangular obstacles have shown to impose a more significant attenuation effect on shock waves than the commonly-used rectangular obstacles in tunnels.