Although catheter ablation therapy is less invasive than surgical procedures and has clear results, the potential for complications exists as with any clinical treatment, especially invasive treatments. The complications common to all catheter ablation treatments can be broadly divided into 3 areas: vascular puncture, catheter manipulation, and the ablation process. Vascular puncture complications include hematoma, deep vein thrombosis, arteriovenous fistula, and hemopneumothorax. Some patients with arrhythmias require atrial septal puncture during the operation. The complication of atrial septal puncture is mainly pericardial tamponade due to cardiac perforation. Cardiac perforation causing pericardial tamponade is also a possible complication of catheterization and ablation procedures. The types of complications during catheterization and ablation may also vary between different types of arrhythmia ablation therapy and are addressed in the following monographs. Catheter ablation therapy is a relatively mature treatment for arrhythmias, and the occurrence of complications is not absolutely avoidable from a scientific standpoint, but the chances are relatively low. The benefits of ablation treatment far outweigh the possible risks, which is why the treatment has been promoted, popularized and developed, and patients do not have to worry too much about the occurrence of complications during the consultation and treatment. Generally speaking, patients can rest assured that their doctors at regular and large hospitals are well aware of the possible complications at each step and try to keep them to the lowest possible level.