To address the issues of large footprint, complex configuration, and lack of flexibility in switching associated with traditional passive filters in high-voltage direct current (HVDC) systems, this paper proposes a hybrid active power filter (HAPF) solution. The HAPF integrates a passive filter and a voltage source converter (VSC) in series, employing two control strategies: current control to compensate harmonic currents and impedance control to enhance low-impedance filtering performance. One HAPF is capable to filter multiple harmonics, and can reach a filtering rate 95% at low frequency and 70% at high frequency. By optimizing the tuning frequencies and reactive power capacity of the passive filter, as well as the configuration of VSC modules, the design improves equipment reliability. Additionally, the incorporation of current-limiting reactors and startup capacitors ensures operational stability. Simulation and field tests demonstrate that the HAPF effectively filters harmonics up to 2500 Hz, significantly suppresses background harmonics such as the 5th and 7th orders, and has been successfully applied in the Fujian-Guangdong back-to-back HVDC project. Replacing all traditional passive filters, the HAPF passed various critical tests, including harmonic generation, grounding faults, and high-load operations, exhibiting stable performance and superior filtering capabilities. This solution overcomes the limitations of conventional approaches and provides a novel method for enhancing HVDC system performance.