1. An optical distance measurement method, comprising: acquiring a plurality of sensed values based on detecting light; performing a filtering operation to select a plurality of selected sensed values from the plurality of sensed values; determining a location of a center of gravity according to the plurality of selected sensed values; and calculating a plurality of depth values with respect to a plurality of detecting points according to the location of the center of gravity and a plurality of depth information transformation functions respectively corresponding to the detecting points.