In this paper, a kind of electromechanical integrated toroidal actuator is presented. In the actuator, the toroidal drive, power and control are integrated. The basic structure and operating principle of the actuator are introduced. The parameter relationship for the actuator is presented as well. The forces between the planet and the worm or between the planet and the stator for the actuator are analysed. The magnetic circuits of the stator, worm, planet and the total actuator are analysed. The results are useful in design and manufacture of the actuator.