A motor, a compressor and a refrigeration device are provided. The motor has a stator and a rotor. The stator has an annular stator yoke and multiple stator teeth located on an inner side of the stator yoke. The stator teeth are provided at intervals along a periphery of the stator yoke. The rotor is provided in the stator. The rotor has an annular rotor yoke and multiple rotor teeth located on an exterior of the rotor yoke. The rotor teeth are provided at intervals along a periphery of the rotor yoke. A tooth width of the stator teeth is T1 and a width of the stator yoke is T2, and T1 and T2 are defined by 4.8≤T2/T1≤5.1. A tooth width of the rotor teeth is L1 and a width of the rotor yoke is L2, and L1 and L2 are defined by 6.1≤L2/L1≤6.3.