In　this　paper,　a　new　traceable　method　for　measuring　RF　AM　signal　is　presented.　The　50GHz　broadband　sampling　oscilloscope　which　is　the　national　pulse　parameter　reference　is　used　to　measure　the　RF　AM　signal.　A　waveform　measurement　system　for　radio　frequency　amplitude　modulation　signal　is　constructed.　After　correcting　the　time-based　jitter　error　of　the　collected　waveform,　the　phase,　amplitude　and　frequency　parameters　of　radio　frequency　amplitude　modulation　signal　are　accurately　restored　by　the　co-directional　orthogonal　method　and　the　least　square　method.　The　experimental　results　show　that　the　method　of　using　broadband　sampling　oscilloscope　to　measure　the　RF　amplitude　modulation　signal　and　digitizing　demodulation　signal　has　excellent　results,　which　achieves　the　accurate　recovery　of　waveform　parameters,　and　provides　a　new　idea　for　traceability　measurement　of　time　domain　RF　modulation　signal.　©　2019　IEEE.