To achieve focus bar codes to be identified and transferred to the computer, a multi-position bar code scanning system was designed based on virtual instrument technology. Taking virtual instrument as the core, the system was configured with high performance bar code scanner and communication between PC and an external device was achieved by RS232 data transmission lines. Based on the virtual instrument development platform, using short period, low cost, graphics programming features of the LabVIEW programming, aiming at the practical application need, LabVIEW program was implemented to realize the communication between host and scaned bar codes and multi position display function. Testing shows the system can read bar codes from bar code scanner and multi-station appear them; this system has the characteristics of high test speed, flexible operation. Data communication between LabVIEW program and bar code scanner is implemented. It provides a new way to control external devices through software.