The　harmonic　magnetic　field　detection　method　has　the　advantage　of　a　large　lifting　height,　which　is　particularly　beneficial　for　the　detection　of　steel　pipelines　without　removing　cladding.　However,　it　has　the　problem　of　strong　coupling　between　the　excited　and　induced　magnetic　field　signal,　which　limits　its　detection　accuracy.　In　this　work,　we　propose　a　differential　compensation　probe,　which　can　effectively　suppress　the　excitation　magnetic　field　signal　in　the　detection　signal,　in　order　to　significantly　improve　the　accuracy　of　the　harmonic　magnetic　field　detection　method.　The　defect　detection　capability　of　the　probe　is　verified　both　by　the　finite　element　simulations　and　experiments.　Despite　its　simple　structure,　the　differential　compensation　probe　greatly　improves　the　signal-to-noise　ratio　of　the　detection　signal.　It　is　expected　that　the　detection　method　based　on　the　differential　compensation　probe　will　have　a　broad　application　prospect　in　the　detection　of　pressure　pipelines　and　vessels　with　cladding　layers.