The coronary artery occlusion (CAO) acutely comes to human, and it highly threats the human's life. When CAO detected, percutaneous coronary intervention (PCI) should be conducted timely. Before PCI, localizing the CAO is needed firstly, because the heart is covered with various arteries. We handle the three kinds of CAO in this paper and our purpose is not only localization of CAO but also improving the localizing performance via preprocessing method. We improve the area under the receiver operating characteristics curve at CAO site localization from a minimum of 0.150 to a maximum of 0.372 via our noise reduction and pulse extraction‐based method. © 2020 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.