Using face images in the diagnosis of Obstructive Sleep Apnea （OSA） in children can reduce the burden of doctors and improve the accuracy of diagnosis. Firstly， the current methods and their limitations of OSA in children clinical diagnosis were briefly described. Then， on the basis of studying the existing methods， combining with the methods of computer-aided face diagnosis of other diseases， the computer-aided face diagnosis methods of OSA in children were divided into three types： traditional computer-aided face diagnosis methods， transfer learning based diagnosis methods， and 3D face data based diagnosis methods. The key steps of the three types of methods were summarized， and the methods used in these key steps were compared， which provides different entry points for the future research of computer-aided face diagnosis for OSA in children. Finally， the opportunities and challenges in the future research of OSA in children diagnosis were analyzed.