The present invention provides a real-time face 3D reconstruction system on a mobile device, comprising: a data preprocessing module, a face model iteration module and a 3D rendering module. The data preprocessing module is connected to the face model iteration module and transmits data and/or signals to the face model iteration module, and the face model iteration module is connected to the rendering module and transmits data and/or signals to the rendering module. The present invention also provides a real-time face 3D reconstruction method on a mobile device. The present invention only needs an image acquired by a single camera to reconstruct a face model without any manual calibration.