A method and an apparatus for detecting an object are disclosed. The method comprises the steps of obtaining a plurality of depth images of the object; extracting foregrounds; fusing the foregrounds in a unified three-dimensional world coordinate system; calculating an appearance two-dimensional histogram from the fused foreground by the following steps of dividing the foreground into vertical members and getting statistics of the numbers of foreground points in the vertical members so as to obtain the appearance two-dimensional histogram; determining an overlapping region and the number of overlaps based on the placement of stereo cameras; determining a detection parameter relating to a detection position based on the overlapping region and the number of overlaps; and detecting the object by the appearance two-dimensional histogram based on the determined detection parameter.