To resist water sloshing loads in the fish water tank, the platform needs to be designed to meet operational requirements and standards. According to ship form parameters and tank type to determine sloshing loads on the platform, and then uses the direct calculation method, built finite element model including the part of the structure of the platform, loading the local loads and global loads act on the compartment structure, check the platform strength under local loads combined with global loads. Through calculation and analysis, the results show that the design of the platform meets the standard requirements, the platform structure belongs to the other items of the structure classification, the standard is 195 N/mm2, and the maximum stresses of the operation platform structure are 124N/mm2. So the sloshing loads have the greatest influence on the strength of the platform. The method of the sloshing load calculation and strength analysis of the operation platform can provide a reference for the subsequent ship design.