Abstract: This paper has studied the kinematics and the precision of a ship block merging system based on the multi-robot coordination. In coordination with the characteristics of the blocks merging technology,the boat blocks trajectory planning method and merging control scheme were presented. After that,we discussed a number of error factors,which may affect the system precision. The simulation results and theoretical analysis show that,the merging system's precision can be guaranteed with the proposed methods even there are significant dimensional errors of the system structure.