In view of the current situation in the daily operation and maintenance of the distribution network and the modern marketing management, the large number of distribution stations and scattered distribution of users, the poor consistency between the line and the user map, the large number of abnormal types, the few analysis tools and the heavy loss reduction task, the distributed load monitoring and abnormal diagnosis technology of the distribution network is comprehensively studied by using the system integration technology of "big, cloud, mobile, intelligence", and the distributed load monitoring terminal and micro-application APP of distribution network are developed to realize highprecision three-phase voltage, current and power. It has the functions of harmonic calculation, unbalance degree calculation, voltage deviation calculation, abnormal wiring diagnosis alarm, neutral line zero sequence current measurement, zero sequence current limit alarm and so on. The pilot application shows that the distributed load monitoring terminal of distribution network can realize the precise positioning of the topological relationship, operation situation, voltage quality and line loss of 10 kV and 0.4 kV lines and the precise positioning of measurable and abnormal situations, which can improve the operation and management level of distribution network for the first-line operation and maintenance team at the grass-roots level, which has great application value.