Abstract: The high temperature characteristics of high voltage organic chip tantalum capacitors are the bottlenecks to limit the wide applications of capacitors. At present, the temperature limit of 105℃ is widely used in the world, but cannot meet the special requirements of 125℃ environment. By the "shielding" and pretreatment of the dielectrics, the post treatment of the organic solid electrolyte, and the improvement of encapsulation layer, the high temperature characteristics of high voltage organic chip tantalum capacitors are significantly improved, and therefore the life tests of 105℃, 2 000 h and 125℃, 2 000 h have passed safely. This study will provide a technical support for the applications of organic chip tantalum capacitors in the special environment.