A　self-made　line　laser　liquid　level　measurement　system　was　used　to　measure　the　fluctuation　of　molten　metal　free　surface　under　pulsed　magnetic　field.　The　electromagnetic　characteristics　of　pulsed　electromagnetic　force　were　mathematically　analyzed.　Results　showed　that　the　electromagnetic　force　presents　oscillatory　attenuation　during　a　single　pulse　period.　The　electromagnetic　force　was　composed　of　turning　force　fturn　and　non-turning　force　fnonturn　The　direction　of　fturn　was　always　consistent　with　the　melt　circumferential　direction,　which　turned　the　fnonturn　consisted　of　electromagnetic　pull　and　push　forces,　which　caused　the　melt　to　oscillate.　Under　the　pulsed　magnetic　field,　the　free　surface　formed　a　meniscus　with　a　high　middle,　low　side　structure.　With　increased　pulsed　field　intensity,　the　center　surface　of　molten　melt　had　an　oscillation　of　3.52　mm　at　0.187　T.　The　wave　power　density　had　only　two　spectral　peaks　(at　0.60　and　3.36　Hz)　without　a　magnetic　field.　Under　pulsed　magnetic　field,　four　spectral　peaks　were　found　at　0.40,　3.00,　6.50　and　13.00　Hz.　©　2020　The　Author(s).　Published　by　IOP　Publishing　Ltd.