The present invention discloses a method of preparing a broad spectrum vaccine for preventing avian colibacillosis , including recombining the tsh gene, which has an adhesive attraction effect with E.coli BL21 (DE3); the resulting vaccine may preferentially bind to the corresponding receptors on avian body cells , resulting in there being no receptors to bind to the pathogenic E.coli, thus decreasing morbidity rates among avians.