In　this　paper,　a　page-checking　instrument　via　MCU　Atmega128　and　an　algorithm　of　fuzzy　pattern　recognition　is　developed　for　automatic　bookbinding　machines.　This　instrument　detects　dynamically　wrong　pages　locating　in　many　word　pages,　graphic　pages　and　word-graphic　pages,　and　at　the　same　time,　sends　messages　to　automatic　bookbinding　machine　that　lets　wrong　pages　pass　as　soon　as　receiving　messages.　This　instrument　can　communicate　with　computers　by　RS232　protocol,　too.　A　detecting　algorithm　developed　via　theory　of　fuzzy　pattern　recognition　is　stored　in　page-checking　instrument.　And　this　instrument　detects　wrong　pages　with　two　detecting　modes,　one　is　self-adaptive　detecting　mode,　the　other　is　non　self-adaptive　detecting　mode.　Experiments　show　that　precision　of　this　instrument　is　0.5%,　and　also　posses　fine　stability.　©　2006　IEEE.