A　new　method　was　promoted　to　extend　the　measurement　function　of　oscilloscope　in　this　paper.　Nose-to-nose　technology　was　used　to　achieve　the　impulse　response　of　any　oscilloscope　which　bandwidth　is　lower　than　50GHz.　By　using　of　deconvolution　algorithm,　the　original　signal　can　be　reconstructed　from　distortion　measurement　data.　Theory　analysis　was　made　in　the　paper,　and　simulation　and　experiment　verified　the　method　The　method　corresponded　to　extend　the　efficiency　bandwidth　twice　or　three　times.