The structure of self-check system in libraries was introduced, and some self-check systems from several manufacturers were tested. The existing problems were illustrated and analyzed, and the position of barcode on the cover of books was discussed. Quantitative testing results were given by testing the average time of book borrowing and returning, abnormal conditions, multi-book detection, reader evaluation, security and functional of magnetic stripe verification, which could provide reference for the research and procurement of self-check system.