Using the typhoon forecasts from National Meteorological Center, the observation data of China’s automatic weather stations, ERA5 reanalysis data, main operational numerical models and ensemble forecasts, the evolution and track forecasting difficulties of Typhoon Gaemi (2403) during different stages are analyzed. The results are as follows. (1) Gaemi successively made landfall in Yilan, Taiwan and Putian, Fujian, bringing widespread and intense wind and rain impacts. The daily precipitation at 14 national meteorological observing stations broke historical records, demonstrating strong extremity. (2) During the formation stage of Gaemi when the atmospheric circulation is in a dynamic adjustment stage, it forms concurrently with Typhoon Prapiroon. The binary interaction between the two typhoon vortices further adds the difficulty of track forecasts. Although subjective forecasts have positive skill of corrections, significant deviations still exist in the typhoon track forecasts. (3) The complex terrain of Taiwan causes high uncertainty into the track forecasts of Typhoon Gaemi before and after it crosses the Taiwan Island, greatly increasing the challenge of accurate landing forecasts. However, high-resolution numerical models have certain advantages in forecasting small-scale fluctuations (such as track loops) in the track under complex terrain conditions. (4) After landing in Putian, Fujian, Gaemi suddenly turns to move westward in the northwest of Jiangxi, leading to significant deviations both in the track forecasts by numerical models and National Meteorological Center. This is because Gaemi is in a complex saddle-shaped environment, where its movement is extremely sensitive to minor changes in the surrounding circulation systems. (5) Nevertheless, AI models such as Fengqing demonstrate unique advantages in forecasting the westward turn of the track. In the future, forecasters should enhance the understanding and application of AI meteorological models. The factors influencing the typhoon track over land are complex, making the forecasting much more challenging than that over the sea. It is necessary to conduct in-depth research on the mechanisms of changes in the typhoon track over land to enhance the understanding of them.