Offshore accurate replenishment technology is the foundation for conducting ocean research for every country. However, it is difficult to keep the security and accuracy of hoisting due to the fact that waves will let vessels generate 6-DOF motions. This paper regards accurate offshore supplying as a background, and takes into consideration that vessel acts as a rigid body to perform algorithm research on the AHC (Active Heaving Compensation) detection system. The binocular camera installed on the hoisting equipment can calculate the 6-DOF pose of vessel via detecting landmarks on the deck. The system can achieve all-weather operations, adopting Shi-Tomasi algorithm to identify and L-K Optical Flow algorithm to track sub-pixel points. Lastly, the scheme has been verified in the 6-DOF motion platform, which indicates that its accuracy meets the requirements of the control experiment in the next step.