The invention belongs to the field of radar imaging, and discloses a radar forward-looking imaging method based on a GPU (Graphics Processing Unit). The method comprises the following steps: at a GPU side, acquiring an observation vector of a receiving antenna to a target scene, gridding the target scene, acquiring a measurement matrix corresponding to the grid range of a target, and building an optimization model for restoring a scene target backward scattering coefficient from the observation vector; at the GPU side, acquiring the observation vector and the measurement matrix from the GPU side, and using a CUDA (Compute Unified Device Architecture) to restore a scene target backward scattering coefficient vector from the observation vector in parallel; and at the GPU side, acquiring the scene target backward scattering coefficient vector from the GPU side, and making the scene target backward scattering coefficient vector correspond to the grid range of the target to get an estimation model of a three-dimensional scene target, thus completing radar forward-looking imaging. The method is used to improve the efficiency of radar forward-looking imaging, and achieve the purpose of real-time radar echo data processing.