The present invention relates to a living body detection method and living body detection system capable of realizing living body detection of a human body, and a computer program product. The living body detection method comprises: respectively using each light source of at least two light sources arranged at different positions to illuminate a face of an object to be detected; capturing a plurality of images of the face of the object to be detected that is illuminated by each light source; calculating a difference image between the plurality of images; and obtaining a detection value of the difference image, and determining that the object to be detected is a living body if the detection value is greater than a pre-determined threshold value.