Time delay estimation is the basis of target location of multi-sensor network, while the basic analysis of the signal is of key importance to the time delay estimation. In this paper, a time delay analysis system is designed by virtual instrument development tools. The analysis system contains: virtual oscilloscope, virtual spectrum analyzer, virtual filter and virtual time delay analyzer. Using this analysis system on a set of field collected acoustic target signal, spectrum analysis and filtering is made. Then the time delay estimation has been carried out for several sampling data segments selected by certain rules, and curve of the time delay vs. time is given. Analysis shows the main frequency of the target signal: 85Hz, 13Hz, 170Hz and 125Hz. The regular pattern of the time delay curve is consistent with the target motion. Application reveals that the system is helpful in the research of time delay estimation.