The invention relates to a low-
noise stable permanent 
magnet switch 
reluctance motor and a manufacturing process and a heat dissipation method thereof. A permanent 
magnet circular ring is fixed to a rotor bracket of the motor, the permanent 
magnet circular ring is formed by an even number of stepped circular-arc-shaped permanent magnets in a head-
tail oppositely matched mode, the magnetic polaritydirection of the circular-arc-shaped permanent magnets is radial, and the 
magnetic polarity of the adjacent circular-arc-shaped permanent magnets is different. When a double-magnetic-polarity cambered surface part section of the permanent magnet circular ring passes through a 
stator excitation salient pole pair, the change of magnetic acting force between the 
stator excitation salient pole pair and the rotor permanent magnet circular ring is obviously slowed down, and thus the motor operates more stably. Through the manufacturing process provided by the invention, a basic condition is createdfor improving the 
machining precision and the 
assembly efficiency of the motor. Various heat dissipation methods are ingeniously fused into overall design and manufacturing of the motor, 
convection heat dissipation of the motor structure, conduction heat dissipation of a 
metal material and heat-conducing heat dissipation of heat-conducting 
sealant are fully considered, and thus the optimal heat dissipation effect of the motor is achieved.