A rankine cycle system (1), a rankine-refrigeration cycle system (2) and a refrigerated vehicle are disclosed. The rankine cycle system (1) comprises a first evaporator (11), an expander (12), a condenser (13) and a refrigerant pump (14) connected in sequence to form a cycle, wherein the rankine cycle system (1) further comprises an electric heating device (15) connected between the refrigerant pump (14) and the expander (12) for heating the refrigerant. When the rankine cycle system (1) has no waste heat source, the present application can continue to provide energy to the rankine cycle through the electric heating device (15), thereby enabling the expander (12) to continuously and effectively output mechanical work. Even without a waste heat source, the rankine cycle can still operate normally, thus adapting to more operating conditions.