To speed up the research pace of domestic electronic testing for raw silk in China, the hardware and software of single-spindle, the general design programs of multi-spindles, the solutions and theories of the existing domestic and international electronic testing for raw silk were discussed and summarized to form an electronic testing system and develop a software package. The system was supported by development environment of Virtual Instrument, the thread guide bayonet and circuit frequency of SD-1(a kind of raw silk instrument) sensor were improved to make the information of the raw silk size and faults into the computer accurately by DAQ in hardware. As far as software was concerned, a special program was designed based on virtual instrument. Serials of information data（voltage values）of the raw silk size and faults was get by the measurement of several groups of raw silk with this system. The testing results of the raw silk size and faults were acquired by the analysis of the fluctuating information data of the raw silk size.