Low-frequency communication constitutes a vital component of essential communication systems, serving a pivotal role in remote radio communication, navigation, timing, and seismic analysis. To enhance the predictive precision of low-frequency skywave propagation and address the demands of engineering applications, we propose a high-precision prediction method based on the ITU-R P.684 wave-hop theory and real-time environmental parameter forecasts. This method features several distinctive attributes. Firstly, it employs real-time ionospheric prediction data instead of relying on long-term ionospheric model predictions. Secondly, it utilizes a detailed map of land–sea surface electrical characteristics, surpassing the simplistic land–sea dichotomy previously employed. Compared with measured data, the findings demonstrate that we attained a reasonable propagation pattern and achieved high-precision field strength predictions. Comparatively, the improved method exhibits an improvement in the time and spatial domains over the ITU-R P.684 standard. Finally, the improved method balances computational efficiency with enhanced prediction accuracy, supporting the advancement of low-frequency communication system design and performance evaluation.