Sympathetic explosion of detonators in chipboard was studied. The parameters of shock wave acting on detonator were measured by PVDF gauge with sensing position area 1 mm×1 mm. The results show that the sympathetic explosion of detonator depends on both the shock pressure peak and its duration,and the shock pressure peak is the chief factor. When the shock pressure peak exceeded 1.29 GPa,the sympathetic explosion happened. But when it fell to 1.0 GPa,the sympathetic explosion was not observed even the shock wave had a longer duration. The delay time was observed in sympathetic explosion of detonators,moreover,the delay time increased with the decreasing of shock wave pressure.