A multi tone modulation system design and development with a low-cost and high performance was developed, taking LabVIEW as the software development platform and the computer sound card as the hardware platform. The system is capable of audio signal acquisition, multi tone modulation, demodulation, waveform and spectrum analysis, and other functions. Actual application shows that the system is not only high accuracy, and reliable, stable performance, easy to operate and extensions. The signal collection technology based on the sound card and the combination of virtual instrument has a broad application prospect in engineering survey and practical teaching.