Roll-on/roll-off (RoRo) ships offer distinct advantages in the maritime industry when it comes to transporting wheeled cargos and super-large vehicles. As the scale of RoRo fleets continues to grow, RoRo shipping companies face the challenge of efficiently organizing multiple ships to meet transportation demands across various regions, ensuring order fulfillment, and minimizing costs. In light of these challenges, we introduced and explored the multi-vessel RoRo ship scheduling, routing and stowage problem (m-RSRSSP), and proposed a mixed-integer linear programming (MILP) model to address this problem. Compared with previous studies, this paper enriches fleet's decision-making and address scenarios where multiple cargos are considered at one port on the basis of integrating ship scheduling, routing and stowage problem of ro-ro ship, which is better aligned with the requirements of certain practical scenarios. Given the intricate nature of this model, we developed a heuristic algorithm rooted in tabu search, incorporating a nested greedy approach. Furthermore, we presented a case study involving deep-sea RoRo transportation between Northeast Asia and Europe. The experimental results validate the efficiency and reliability of the proposed heuristic algorithm in solving large-scale problems, and provide valuable strategies for the formulation of the RoRo fleet operation schemes.