The invention belongs to the technical field of dispatching automation of power systems, and aiming at the problem of a pre-warning difficulty for a power network failure caused by big data of a smart power network, provides a power network operation event-oriented monitoring, pre-judging and analyzing system on the basis of a big data technology. The system comprises a power network data analysis part and an expert database part, wherein the expert database part takes charge of storing various data in an equipment failure or a power network event; and the power network data analysis part analyzes the big data. The system provided by the invention has the beneficial effects that (1) a self-learning expert database for the smart power network is created under the age of big data to play a key role in monitoring and pre-warning power equipment and power network accidents; the monitoring and pre-judging accuracy and speed are greatly improved; and the system assists a power enterprise in relatively well finishing the monitoring and pre-judging work, and has positive practical significance; and (2) the influence on an equipment operation condition and a power network event state caused by monitoring quantities is comprehensively and accurately considered by timely updating weights and thresholds of various nodes; a timely pre-warning function is achieved; and the system has practical application value in research of the smart power network in the future.