To solve complex grid faults, a portable fault recording and message analysis device based on mobile internet is needed. The device can help us get accurate assessment of fault nature, fault location result and failure severity. Based on the characteristics of mobile terminals, this paper redesigns the function modules of acquisition, analysis and sharing of recorded data. In addition, the device adds the function of differential calculation and analysis of multi-source recorded data, which can quickly confirm the fault point and judge the correctness of the protection action behavior. Many practical application cases show that the device can realize intelligent and convenient fault analysis, improve the level of fault analysis and processing efficiency effectively, reduce the time of fault recovery and enhance the reliability of power supply. This work is supported by National Key Basic Research Program of China (973 Program) “Basic Subject issues in Efficient Energy Use” (No. 2010CB736204) and Science and Technology Project of Zhejiang Electric Power Co., Ltd. (No. 5211WZ15013Q).