Abstract: Based on the demands of distribution systems and the development trends of digital technology, the digitalized active distribution system (D-ADS) was analyzed. The development status of digitalized distribution system was briefly summarized. On this basis, the definition and main characteristics of the D-ADS were refined preliminarily, and the conceptual model of the D-ADS was formalized by applying the model based system engineering. Then, technical applications of the D-ADS were explored by taking two examples from two perspectives including digitalized distribution equipment and digitalized distribution system. Besides, technical challenges and relevant development suggestions of the D-ADS were put forward. The characteristics of the D-ADS were concluded.