Abstract: Synchronous run-length DSGM-SC compression technique is presented in this paper for one-dimensional random signal with local fast variation and expansive slow variation. First, run length DSGM detection is implemented to detect fast variation part, then the fast parts spectrum is compressed with interpolation as optimal times principle to improve integrative correlation, and transform coding is adopted to get high compression ratio. Data files, which include high and low spectrum information, are synchronously compressed. Position information is prerecorded to fulfill time recover without distortion. The compression ratio with the method can reach 32.4 to electrocardiogram data recorded by multi-functional bedside instrument of NEC, BSM8300 while the fidelity of medical treatment is high. The research has application in one-dimensional data analyzing, recording, transmitting and integrated service.