In order to research the effect of MEMS (micro-electromechanical systems) fabrication process based on one side etching on mode-localized accelerometer, effects of adhesion and footing on mode-localized accelerometer was investigated by analyzing the effect of release and etching on the device structure, amplitude-frequency characteristic and initial working point. The results show that when the oxide layer is released, the device layer is easily adhered to the substrate due to the presence of the liquid tension, thus, the device failure happens. And the mass mismatch of the weakly coupled resonators is induced by the footing phenomenon, then a large initial amplitude ratio drift is generated and it is difficult to measure the signal. It is concluded that uncertainty of mode-localized accelerometer is induced by the MEMS fabrication process based on one side etching.