A flexible self-adaptive composite carbon brush-type electromagnetic composite field synchronous laser cladding device, comprising an electromagnetic field synchronous coupling module that processes a part to be processed, a mechanical arm that drives the electromagnetic field synchronous coupling module to move, and a laser that generates laser; the electromagnetic field synchronous coupling module comprises a laser head, an electric field portion and a magnetic field portion; the magnetic field portion comprises two magnetic field generating modules, and the electric field portion comprises two electric field generating modules, the magnetic field portion and the electric field portion both being fixedly erected at the periphery of the laser head by means of a supporting structure. This invention adopts four sets of coil parts arranged in the annular circumference, and continuous adjustment of the magnetic field size can be realized with the external magnetic field power supply, and the size meets the use requirement; the design of the pointed part of the iron core head improves the magnetic field intensity and linearity of the processing surface. The supporting structure ensures simultaneous follow-up coupling of the electric and magnetic fields.