The trajectory generator is an important tool for the algorithm research and simulation verification of inertial navigation systems and their integrated navigation systems. By exploring and analyzing the research status of trajectory generators in different carriers, the design methods and main ideas of the ideal, numerical algorithm and mathematical model trajectory generators are outlined, and the research focuses are summarized. The three types of trajectory generators are then simulated and compared, and their characteristics and problems are analyzed. Finally, possible prospects for the next step in trajectory generator research are briefly discussed, providing ideas for future research in this field.