Abstract: Wave-equation prestack depth migration is a pivotal technique in seismic imaging, widely employed for high-resolution structural imaging and hydrocarbon reservoir prediction in complex geological settings. In recent years, substantial advancements have been made in algorithmic optimization, numerical implementation, and multi-wave imaging. This study provides a comprehensive review of three developments within the wave-equation prestack depth migration framework, focusing on one-way wave migration, two-way wave depth migration, and reverse time migration (RTM). The review emphasizes the historical development, key characteristics, and practical applicability of each method. One-way wave migration offers rapid imaging but with limited accuracy. In contrast, RTM accounts for full waveform propagation, enabling high-precision imaging in complex media, though at substantial computational cost. Two-way wave depth migration strikes an optimal balance between accuracy, efficiency, and adaptability, positioning it as a promising approach for next-generation high-precision seismic imaging. Moreover, the integration of artificial intelligence and multi-source data fusion into migration methodologies offers further potential for enhancing both imaging accuracy and computational efficiency. This review aims to serve as a valuable reference for ongoing research in wave-equation migration and to provide insights into future directions of imaging technologies in complex geological formations.