For the detection problem of data packet loss in data acquisition and processing system, according to thecorrelation waveform invariance of continuous sinusoidal signal, a detection method of data packet loss based on correlationwaveform invariance was proposed. In the method, the packet loss of the data was detected according to the variation of thecorrelation waveform, the autocorrelation waveform of narrowband data was obtained by autocorrelation processing the output dataof the data transmission unit. When the output data of the data transmission unit lose data packet, the data would change from singlecode phase modulation to multi-code phase modulation, that would change the data bandwidth and autocorrelation waveform. Basedon that, the data packet loss can be detected and determined in the data transmission unit. Theoretical analysis and experimentalresults show that the method is feasible and effective.