Abstarct: In many applications such as submarine propulsion systems, need for different powers in wide range, various speeds and operating in fault conditions, the machine must be designed that is provided high torque and required power at constraints such as low size and weight, high reliability, easy maintenance, low noise and vibration and multi voltage power supply. The study on many machine structures shows that multi-laxyer permanent magnet machines are appropriate for these applications. These motors can be used in different speeds proportional to required power which is performed through laxyer switching appropriately. So, the motor operates in the rated power which is caused to increase efficiency. Among permanent magnet machines, axial flux machines due to type of their special structure are appropriated for operating as multi-laxyer system. In previous papers, has not been enough attention about multi-laxyer permanent magnet machines designing. This thesis will discuss how to choose the number of laxyers during multi-laxyer machine designing in high power range. Also, transient-dynamic performance of the machine is investigated in the laxyer switching conditions in different loads and speeds via performing simulations. In the end of this thesis, a pattern is offered to appropriate laxyer combinations for providing required power in the various speeds to reach good performance indexes.