Most AUVs are underactuated and their trajectories are high-order differential curves and local reachability. Therefore, AUVs are highly likely to experience a bottom-up collision and damage where terrain fluctuations exceed their tracking ability. This article proposes a seabed extreme tracking path transformation method to solve this problem. Firstly, solve the extreme tracking path based on the prior DEM and the tracking altitude constraints. Then, the geometric constraints of the seabed tracking path are established through the AUV dynamics constraints, and the limit tracking path is transformed to meet the geometric constraints, thereby obtaining an effective path that satisfies the tracking altitude constraints and AUV dynamics constraints. The simulation experiment with an actual seabed terrain map shows that the method proposed in this paper can effectively avoid collisions, reduce the tracking error while tracking continuous undulating terrain, and reduce the largest altitude exceedance of AUVs following tracking from 73% and 69.7% to 6%, thereby improving the safety of AUVs while following the seabed.