A portable data acquisition and analysis system was developed. This system was used to diagnose faults of mechanical equipments. A structure of principal and subordinate was adopted by the instrument: the former was based on Labview, and it achieved the management of trails, data and communications and the analysis of signals; the latter was used for data acquisition and data analysis. The subordinate consisted of hardware layer, hardware-driven layer, operating system layer, application software layer and commutation layer between the upper and the lower system. The kernel of hardware layer was a SoC; our laboratory’s RTOS: TDNC-OS was transplanted into the SoC as its operating system layer, and the division of tasks was given; a principle of buffer zone was introduced into the application software layer; UART module was the main part of communication layer. Finally, an example was given to show that the system run accurately in practice. The prototype of the instrument has been produced, and it is well-functioning.