Abstract: In the field of electric drive contra-rotating propulsion, the transverse-dislocated magnetic-field-modulation brushless dual-rotor machine (TDMFM-BDRM) has the characteristics of no rotating winding and can output equal-opposite torques at any time, which solves the problems of poor reliability caused by the rotating winding or the difficulty in the coordinated control of dual-rotor torque in the conventional contra-rotating machines. In this paper, the research on the TDMFM-BDRM is carried out. Based on the three-dimensional magnetic-field-modulation principle and winding function, the influencing factors of electromagnetic torque and variation law are analyzed. The magnetic block skewing effect of the transverse-dislocated structure in the modulating rotor is revealed, and the influences of permanent-magnet rotor pole-pairs number, multi-unit structures, and the dimensions of magnetic blocks at the ends on cogging torque are studied. The method to reduce cogging torque and torque ripple under the constant output torque is given. The power factor of the machine and its influencing factors are further studied, and the influences of structural parameters and input current on the power factor are given. The prototype of TDMFM-BDRM is manufactured, and the theoretical analysis is verified by experiments.