This paper presents the design, analysis and control of an original low speed and high torque five-phase external rotor permanent magnet synchronous machine (PMSM) applied for the direct drive of coal conveying system. Firstly, the design considerations including the windings factors and the magnetomotive force (MMF) are given. Secondly, according to the performance requirements, the preliminary dimensions of the machine are firstly calculated using the magnetic circuit method, and then optimized using a Kriging model optimization strategy.