The invention relates to microwave and ferrite technology, in particular to a SIW field-shifting isolator with a special-shaped ferrite structure, which is a point-frequency SIW isolator. According tothe invention, a cuboid ferrite block in an original SIW field-shifting isolator is replaced with a row of equidistant ferrite cylinders; therefore, the heat dissipation and miniaturization of devices are optimized through the discontinuous structure under the premise of guaranteeing the device performance. After adding the external magnetic field, the ferrite cylinders can achieve high isolationof the point-frequency and can be applied to Ku band. The SIW field-shifting isolator with the special-shaped ferrite structure solves the problems of poor heat dissipation and poor miniaturization caused by the ferrite morphology of the SIW field-shiftinging isolator in the prior art.