The invention provides a parameter self-adaptive adjustment harmonic compensation method and device. The particle swarm optimization algorithm is adopted for optimizing control parameters of PI control and repetition control; the harmonic current percentage is calculated in the optimization process; the speed of particles in the particle swarm optimization algorithm is adjusted according to the harmonic current percentage; when the harmonic current percentage is large, the search speed of particles in a particle swarm should be increased, the global search capability can be improved, and accordingly the harmonic compensation efficiency can be improved; when the harmonic current percentage is small, the search speed of particles in the particle swarm should be decreased, the local search precision of the algorithm can be improved, and accordingly the precision of harmonic compensation can be improved. According to the invention, the debugging difficulty of manual adjustment by testing personnel is reduced through the particle swarm optimization algorithm, so that the harmonic compensation effect is greatly improved.