A translational stator ring-shaped built-in permanent magnetism eddy current speed adjusting device disclosed by the present invention comprises an input shaft (1) and an output shaft (2) which are arranged coaxially, a built-in permanent magnetism rotor (3) is arranged coaxially on the input shaft (1), and a stator ring (4) which can translated axially is arranged coaxially at the outer circumference of the built-in permanent magnetism rotor (3). A conductor rotor (5) is coaxially arranged on the output shaft (2) and is formed by fixing a copper layer of good conductive performance on a conductor rotor iron core, and the copper layer exactly faces the inner side of the permanent magnetism rotor. The stator ring is composed of the ferromagnetic materials of good magnetoconductivity, surrounds at the outer side of the permanent magnetism rotor, and has an air gap with the permanent magnetism rotor. According to the present invention, by controlling the axial relative position change between the non-rotating stator ring and the permanent magnetism rotor, an air gap magnetic field between the permanent magnetism rotor and the conductor rotor can be adjusted flexibly, and finally the wide speed adjusting range operation is realized.