The invention discloses a fault judgment system for an intelligent power grid, and belongs to the technical field of power grid data collection processing. The data flow reduction degree is high; dataflow of a fault point after data reduction is difficultly lost; and current sensors at nodes of the power grid can be enabled to collect data in a same time section. The system comprises a server arranged in a power grid monitoring center, and a controller, a data processing module, a humidity sensor, a temperature sensor, a wind velocity sensor, a current sensor, a season time period timing module, a peak valley electricity time period timing module, a satellite time corrector and a clock control chip arranged at the nodes of the power grid, and a constant temperature protection mechanism for providing constant temperature protection for the current sensor; and the control ends of the server, the data processing module, the humidity sensor, the temperature sensor, the wind velocity sensor, the current sensor, the season time period timing module, the peak valley electricity time period timing module, the satellite time corrector, the clock control chip and the constant temperature protection mechanism are connected with the controller.