Objectives  To ensure the icebreaking navigation capability of polar bidirectional icebreaker ships, it is necessary to focus on the design of their stern line characteristics.

  Methods  This paper surveys many polar ships in active service, summarizes the current standards, discusses the ice load modes of the pod propulsion units and ice breakage processes of ships, and analyzes the key design characteristic parameters and adaptability of the stern lines of pod-propelled polar ships.

  Results  It was found that the dip angle of the stern transom plate affects the horizontal and vertical forces on the sea ice by ships directly during the ice-breaking processes. This dip angle should be amplified properly to guide the bending fracture of sea ice effectively. The W type of stern plate transverse profile can resolve the contradiction between the optimization of wake field and the outflow efficiency of broken ice. The pod installation base could play a certain ice-breaking function, but it would affect the flow field of the pod. The tail fin would also affect the stern flow field and the outflow of broken ice obviously.

  Conclusions   The reference for the adaptive optimization design of pod-propelled polar ship stern profile can be provided by the research results.