The invention discloses an HVDC (high voltage direct current transmission) direct current active power filter repetitive control method based on system identification. The HVDC direct current active power filter repetitive control method specifically includes: step 1, drawing an equivalent circuit diagram of a topological structure of the HVDC direct current active power filter based on the system identification; step 2, setting up a transfer function for confirming control objects according to control targets which are harmonic current and filtering branch circuit impedance both enabling offset current of a filtering branch circuit to be equal to negative; step 3, assuming control object models according to a system identification based repetitive control theory; step 4, performing system identification based repetitive control on the controlled objects; and step 5, performing cascading PI processing on the controlled objects after being subjected to the system identification based repetitive control. Adverse influence on controlled system performance caused by uncertainty and time-dependent nature of parameters of the controlled objects is overcome, filtering frequency bandwidth has good inhibitory effect on each harmonic wave, controllers are simple in structure, DSP(digital signal processor) implementation is facilitated, and the HVDC direct current active power filter repetitive control method has high response speed and small steady-state errors on the premise of guaranteeing stability.