Korea has transformed itself from a developing country to an Organisation for Economic Co-operation and Development member country and a donor for developing nations. It has ranked among the world's top 10 energy-consuming countries. Its industrial sector depends heavily on the utilization of fossil fuels and consumes more than 45% of national energy expenditure. Plausible concerns about industrial energy inefficiency can upset the structural dependence of the whole Korean industry on the energy sector. Using Korea's industrial input-output data from 2010 to 2012, this research conducts a simulation analysis on trade suspension resulting from shocks provided by each of the six energy industries. This study investigates the propagation of these shocks across 160 industries. We found that the petroleum, electricity, and town gas industries are the most influential energy industries in terms of diffusion of trade shocks to other industries, and the number of propagation steps of energy shocks decreases over time due to the industries' unimproved energy inefficiency. Therefore, governments need to address this interdependence within energy sectors and between energy and non-energy industries, with integrated policies for energy efficiency and contingency plans.