Ultra-high　frequency　adjustable　multi-pulse　(UFMP)　gas　tungsten　arc　welding　(GTAW)　is　an　innovative　approach　that　incorporates　ultrasonic　energy　into　the　GTAW　process　to　refine　the　grain　structure　of　weld　metals,　reduce　welding　residual　stress,　and　improve　the　mechanical　properties　of　weld　joints.　In　this　study,　we　designed　a　UFMPGTAW　power　supply,　with　a　current　change　rate　of　up　to　200　A/mu　s　and　a　frequency　reaching　100　kHz.　A　welding　current　output　waveform　that　undergoes　four　stages　within　one　welding　cycle　was　designed,　and　a　welding　arc　image　acquisition　system　was　established　to　capture　images　of　UFMP　GTAW　arcs.　The　morphological　characteristics　of　the　arcs　generated　by　pulsed　GTAW,　direct　current,　and　UFMP　GTAW　at　the　same　average　welding　current　but　different　frequencies　were　analyzed　and　compared.　Subsequently,　a　mathematical　model　was　established　to　analyze　the　radial　contraction　force　of　the　arcs　using　the　effective　value　of　current.　Upon　analysis,　it　was　found　that　the　higher　the　arc　frequency,　the　greater　the　effective　value　of　welding　current,　resulting　in　a　stronger　radial　contraction　force　and,　consequently,　a　smaller　arc　area.　At　the　same　pulse　frequency,　the　area　of　the　UFMP　GTAW　arc　is　smaller　than　that　of　the　pulsed　GTAW　arc.　This　study　established　a　UFMP-GTAW　experimental　system,　captured　welding　arcs　of　different　frequencies　and　waveforms　using　a　high-speed　camera,　explored　the　compression　mechanism　of　ultra-high　frequency　arcs,　and　provided　new　ideas　for　the　study　of　ultra-high　frequency　arcs.