In paper by finite element method performed mathematical modeling interconnected electromagnetic and thermal processes in electromechanical transducers with magnetic-fluid filling. The dependence of the magnetic induction and distribution of current density in an active portion of the electromechanical transducer filled with magnetic fluid. The results of calculation of the electromagnetic field of the induction motor serial indicate the feasibility of the magnetic fluid in the gap of an induction machine with a classical design. The results of calculation of the thermal field submersible transducer with magnetic fluid filling indicate a high level of specific heat release in its active part. The surface temperature of the rotor in the stop mode, a current value reaches 160-170 oC. Temperature heated by the environment near the rotor surface – 145-155 oC. Electromagnetic torque value calculation suggests that the resultant torque to the two cylindrical portions of the rotor submersible transducer increases by 9 % (156 H∙m) in comparison with an embodiment without the magnetic fluid filling (143 N∙m).