Face attendance machine is the use of high precision technology in todays international science and technology field - face recognition technology (fusion of computer image processing technology and the principle of biostatistics in one), the use of computer image processing technology to extract portrait feature points from the video, using the principle of biostatistics analysis and establish face feature template. When the registered person walks past the face recognition machine, it will have a voice message saying "Hello" or the persons name indicating that attendance has been successful. Moreover, it also has image update function, if the image is taken as the first face, stored for the second face, if the first face image and the second face image is consistent, face recognition attendance machine will automatically store the first face image to update the second face image. This method can keep the users face image updated, reduce the influence of facial shape change on recognition, and increase the recognition accuracy.