1. A human face detection device, comprising: a photosensitive element, for capturing a first image containing a first human face block; a human face detection unit, for comparing the first image with at least one human face feature, so as to detect the first human face block; and a skin color threshold generation unit, for updating a skin color threshold value according to the detected first human face block; wherein the skin color threshold value is used for filtering the first image signal to obtain a candidate region, the human face detection unit compares the candidate region with the at least one human face feature to obtain the first human face block, and/or the skin color threshold value is used for determining whether the first human face block detected by the human face detection unit is correct.