Abstract: The precise measurement of agricultural machinery operation area provides the critical data foundation for agricultural subsidy accounting and intelligent decision-making. Addressing the bottlenecks in measurement accuracy and efficiency caused by trajectory noise, fragmented plots, and repetitive operations in practical production, this paper systematically reviewed area calculation technologies based on agricultural machinery trajectories. At the algorithmic level, the principles, technical characteristics, and applicable boundaries of the mileage-width method, buffer-grid method, and polygon-contour method were analyzed. At the application level, the engineering implementation characteristics of agricultural machinery equipment, UAV platforms, and navigation and positioning enterprises were summarized. Analysis indicated that existing algorithms still struggled to balance accuracy, efficiency, and adaptability, and a unified evaluation standard was currently lacking. Accordingly, future directions were proposed from three dimensions: Multi-source sensor fusion, algorithm lightweighting and edge computing, and intelligent data analysis. This study aimed to provide a reference for the research and application of precise measurement technologies for agricultural machinery operation areas.