Traditional methods of driver's gaze estimation usually need additional equipment to obtain the driver's facial and eye features, which is difficult to apply in real life. In this paper, a gaze region estimation method based on computer vision is proposed, which reduces the hardware requirements of the experiment. In order to achieve this goal, a new eye feature extraction method and an improved random forest algorithm are adopted in this paper. Finally, the driver's line of sight is determined by combining the head and eye features. The driver's head features are obtained by pose from orthography and scaling with iterations (POSIT) algorithm. Then, the accurate positions of the driver's corner of the eye and the pupils are obtained by the from coarse to fine method, and the eye line direction is estimated according to the relative position of the pupil in the eye area. Finally, the improved random forest is used to estimate the driver's gaze region. The experimental results show that the accuracy of this method is 94.12% in the real driver's gaze data set.