The radar seeker simulation system is crucial for the process of the seeker striking the target accurately. As simulation systems become more complex and data processing demands grow, traditional serial computing methods can no longer satisfy the strict real-time requirements of radar seeker digital simulations. To address the challenge of lengthy simulation times in the radar seeker simulation process, this paper proposes a full-process digital real-time simulation method. Firstly, the core components of the traditional full-process simulation architecture—receiving and controlling system commands, simulating echo data reception, SAR imaging processing, uploading imaging results, and dynamically updating the user interface—are restructured into a pipeline-based parallelization framework. Secondly, the SAR imaging algorithm's primary steps are parallelized using the OpenMP multi-core parallel programming model on multi-core CPUs. Furthermore, the high-performance mathematical computing library FFTW3 is introduced to quickly realize the Fourier transform of the imaging algorithm to accelerate the processing speed of the SAR imaging algorithm. Finally, the simulation results show that compared with the traditional serial simulation, the acceleration ratio of the whole process design method reaches about 100 times, and the similarity of SAR images before and after acceleration is close to 1. Under the premise of consistent processing accuracy and effect, this approach enables full-process real-time simulation of the radar seeker system, showcasing promising prospects for practical engineering applications.