The invention discloses a permanent magnet coupler. The permanent magnet coupler comprises a shaft A and a shaft B which are separated, wherein the shaft A and the shaft B are coaxial; a permanent magnet rotary table is arranged on the shaft A; an inner barrel, a carrying magnet and an outer barrel are arranged on the permanent magnet rotary table in sequence from inside to outside; a circle of permanent magnets are mounted on the carrying magnet; the magnetic pole directions of the permanent magnets are vertical to the axis of the permanent magnet rotary table, and the magnetic poles of adjacent magnets are mounted in a heterospolar mode; a conductor rotary table is arranged on the shaft B, one or more conductor barrels are arranged on the conductor rotary table, and the conductor barrels are arranged in the gaps among the inner barrel, the outer barrel and the carrying magnet. According to the invention, N and S poles of the magnets are arranged in an adjacent mode, a magnetic line passes through the corresponding conductor barrel, and when the magnetic line and the corresponding conductor barrel move relative to each other, the magnetic line is cut by the corresponding conductor barrel, eddy current is generated in the conductor barrel, and then an opposite sensing magnetic field is generated by the eddy current, so that the relative movement between the magnetic line and the corresponding conductor barrel is prevented, the torque transmission between the magnetic line and the corresponding conductor barrel is realized, and the purposes of vibration isolation, speed reduction and energy reduction are achieved.