The utility model discloses a power transformer fault detection system based on vibrations. The power transformer fault detection system based on vibrations comprises: at least a vibration sensor fixed on a surface of the power transformer, and a first signal acquisition module, a calculation processing module, and a display output module connected in sequence with the vibration sensor; the first signal acquisition module collects vibration signals outputted by the vibration sensor; and the calculation processing module carries out calculation process to the vibration signals collected by the first signal acquisition module, whether winding deformation faults exist or not is detected, and detection results are outputted through the display output module. Compared with existing power transformer fault detection system based on electric models, the power transformer fault detection system based on vibrations can carry out accurate detection to faults like winding deformation, iron core loosening, and the like, electrically connection with the transformer is not needed, and the system structure is simple.