Abstract: The carrying capacity of submarines is the ability to resist static load, which serves as an important factor in judging the submarine's dynamic unsinkability. Based on the vertical maneuverability motion equation and the longitudinal hydrodynamic force balance, the propeller thrust force is divided into the mooring portion and the relative decreased force on mooring state. Meanwhile, the dynamic motion equation of carrying capacity and the balance equation of carrying capacity are derived. Four criterion and the corresponding analytic expressions about the carrying capacity are presented based on the derived balance equation. Calculation and analysis show that the propeller plays a significant role to the carrying capacity, and the criterion presented in this paper could clearly evaluate the carrying capacity, and its analytic expressions provide the basis for future carrying capacity design.