Failure identification method of optical navigation device

There is provided a failure identification method of an optical navigation device including the steps of: constructing a fixed noise map according to image frames captured by an image sensor; calculating a feature value of the fixed noise map; identifying whether the fixed noise map is uniform or not according to the feature value; and generating an alert signal when the fixed noise map is non-uniform for indicating failure of the optical navigation device. 一种光学导航装置的失效判断方法，包含下列步骤：根据影像传感器获取的影像帧建立固定噪声图；计算该固定噪声图的特征值；根据该特征值判断该固定噪声图是否为均匀；以及当该固定噪声图为不均匀时，产生警示信号以表示该光学导航装置失效。