A method, a device and a system for reporting a Minimization Drive Test (MDT) log result are disclosed by the present invention for ensuring that the MDT log result can be reported in time. The method includes: after a User Equipment (UE) is re-accessed to a target cell from a original cell, if the UE still stores locally an unreported MDT log result, a log available indication can be sent to the target cell by the UE itself or by an Evolved Node Base station (eNB) managing the original cell, and a managing device of the target cell is notified to request the unreported MDT log result from UE. Therefore, the MDT log result is continued reporting in the target cell, and the target cell obtains the log available indication of the UE in time, initiates an acquiring request for the MDT log result to the UE timely and obtains the reported MDT log result in time, thus the collection for the environment information of a network is completed and the environment information is obtained exactly.