The invention discloses a dispatching end grid fault diagnosis method based on wide-area fault recording information. The method comprises the following steps that when a grid breaks down, fault data of a primary system of the grid are recorded according to a certain sampling frequency mode and are sent to a dispatching main station end through a fault recording networking system; the mapping relation between a basic data platform of grid equipment and a fault recording system is established through CT identification; different sampling frequencies of a fault recorder are unified to be the same sampling frequency according to an interpolation method; a differential-current out-of-limit value is set and independent grid equipment serves as a calculation unit to carry out differential-current calculation; whether the differential-current value is out of limit is confirmed to position fault places and confirm protection actions. The dispatching end grid fault diagnosis method has the advantages of solving the key problems that sampling frequency of the fault recorder is different and data are hard to synchronize, and achieves fault diagnosis application functions such as system operation state monitoring, protection behavior analyzing and accurate fault positioning through the fault recording information only.