The characteristics of USB data acquisition system NI cDAQ and its control software LabVIEW are briefed.The methods for controlling GDS pressure and volume controller by LabVIEW through serial port communication are presented.A practical data sharing method among geotechnical testing systems is illustrated.As an application case on a modified conventional soil triaxial testing system, the automatic triaxial testing system is designed by LabVIEW.Based on the control panel, the cell pressure and back pressure can be controlled independently and the testing data can be recorded automatically.