The　introduction　of　ultrahigh-frequency　pulse　gas　tungsten　arc　welding　has　revolutionized　the　precision　of　heat　input　control　in　welding　arcs,　presenting　new　and　promising　research　directions　for　welding　processes.　However,　due　to　current　limitations　in　imaging　technology,　only　steady-state　images　of　the　arc　under　100　kHz　pulse　current　conditions　can　be　captured,　making　it　challenging　to　display　instantaneous　dynamics.　This　has　led　to　a　lack　of　in-depth　studies　on　the　arc　morphology　and　characteristics　of　ultrahigh-frequency　adjustable　multipulse　gas　tungsten　arc　welding　(UFMP-GTAW)　at　this　frequency.　To　bridge　this　gap,　a　transient　two-dimensional　axisymmetric　numerical　simulation　model　for　100　kHz　UFMP-GTAW　was　established　in　this　paper,　based　on　magnetohydrodynamics　and　the　assumption　of　local　thermal　equilibrium.　The　model　used　Maxwell＇s　equations　to　simulate　the　physical　behavior　of　the　arc.　A　100　kHz　UFMP-GTAW　arc　model　was　generated　and　analyzed　using　simulation　technology.　The　results　show　that　the　macroscopic　morphology　of　the　100　kHz　UFMP-GTAW　arc　obtained　through　simulation　remains　highly　stable　within　a　single-pulse　cycle,　which　is　consistent　with　the　actual　steady-state　arc　images.　The　high-intensity　energy　regions　inside　the　arc　exhibit　regular　droplet-like　flows　that　migrate　from　the　cathode　to　the　anode.　Variations　in　the　current,　temperature,　and　current　density　exhibit　asynchronous　characteristics.　The　peak　and　average　values　of　parameters　such　as　the　arc　temperature　and　current　density　have　increased　significantly.　This　method＇s　unique　current　waveform　design　and　ultrahigh-frequency　mechanism　enable　it　to　achieve　a　high-energy　state　of　arc　plasma　at　a　lower　average　current　level,　which　provides　a　reference　for　the　precise　control　of　welding　quality　and　improves　the　welding　energy　utilization　efficiency.