Using an efficient,flexible,express,general test platform provided by NI-Campact DAQ,Selecting the appropriate circuits and chipsand to design a separate signal conditioning hardware module,which could isolate and amplificate the biological input signals,and also separate and drive the output signal.Then we achieved the electrical isolation between the instrument and input and output signals .Using Labview virtual instrument programming language,we constructed and designed an common laboratory instrument for bio-electrical measurement and treatment,which has a very strong expansion and data processing capabilities.The instrument is safe on human and also provides a open,powerful and versatile test platform of teaching experiment for students.