1. A pedestrian detecting system, comprising: a depth capturing unit configured to detect and obtain spatial information of a target object; an image capturing unit configured to capture an image of the target object and recognize the image, thereby obtaining image feature information of the target object; and a composite processing unit electrically connected to the depth capturing unit and the image capturing unit, wherein the composite processing unit is configured to receive the spatial information and the image feature information and to perform a scoring scheme to detect and determine if the target object is a pedestrian; wherein an appearance confidence is obtained through data transformation of the image feature information, and a spatial confidence is obtained through data transformation of the spatial information, and the scoring scheme performs weighted scoring on the spatial confidence and the appearance confidence to obtain a composite scoring value to determine if the target object is the pedestrian.