Time-base　error　is　a　key　factor　affecting　the　accuracy　of　time-domain　measurement　of　bandwidth　sampling　oscilloscopes.　Therefore,　it　is　necessary　to　compensate　the　time-base　error　of　measurement　results,　and　it　is　also　very　important　to　evaluate　the　uncertainty　of　time-base　error　compensation　of　measurement　results.　In　this　paper,　the　estimation　and　compensation　algorithm　of　time-base　error　is　analyzed　firstly.　Then　the　model　of　calculating　the　uncertainty　of　every　point　of　the　measurement　waveform　which　have　compensated　the　time-base　error　is　constructed　based　on　the　covariance　matrix.　Finally,　the　uncertainty　of　each　point　of　the　high-speed　pulse　signal　after　time-base　error　compensation　is　calculated,　and　the　maximum　voltage　value　of　the　uncertainty　components　of　every　point　of　the　measurement　waveform　is　about　2.3mV.　The　maximum　voltage　value　is　calculated　as　the　uncertainty　of　the　rise　time　of　the　measured　signal,　which　is　about　0.24ps.　The　result　indicating　that　the　method　of　evaluation　the　uncertainty　of　the　measurement　waveform　by　the　point-by-point　is　feasible　and　reasonable.