The invention discloses a side view detecting method. The side view detecting method is specifically implemented by detecting and analyzing the change of the direction of the face and comprises the following steps of S1, collecting images, S2, obtaining face images, S3, finding the middle line of the face images and S4 judging whether side view exists or not. The invention further provides a side view detecting system comprising an image colleting device, an image processing and analyzing device and a reminding device. The image collecting deice is used for collecting images containing a viewer. The image processing and analyzing device is used for processing and analyzing the collected images and obtaining a judgment result. The reminding device is connected with the image processing and analyzing device and conducts corresponding processing according to information output by the image processing and analyzing device. The side view detecting method and system have the intelligent detecting and reminding function on a television type side view disease existing among children at present, and the situation that parents need to accompany the children and remind the children all the time is avoided; an infrared emitting source and a radio wave emitting source are not needed, a sensor does not need to be used in cooperation with an emitting source, and the complexity of installation and debugging is lowered.