Abstract: It is a challenging task to predict the outcome of chemical reaction and design the route of synthetic planes in the field of organic synthesis. As a novel strategy, the machine-learning approach has extended to study the task of organic synthesis. Focusing on small organic molecules, this work reviews the progress of organic synthesis by virtue of machine-learning approach, including the dataset collection of chemical reaction, the prediction of chemical reaction and the route of synthetic plans. With respect to the molecules of resin with complicated architecture, this work also comments on the challenging issues for organic synthesis based on machine learning, such as the deficiency and bias of dataset, the ill-defined representation of molecular structures and the machine-learning approach with small dataset.