The invention relates to a preparation method of long-acting composite antibiotic ceramic and belongs to the technical field of ceramic material preparation. Nanometer titania doped with silver ions is prepared through a sol-gel method, and is mixed with other ceramic ingredients prior to sintering to obtain the long-acting composite antibiotic ceramic. The silver ions with antibiotic effect is coated with nanometer titania through the sol-gel method for protecting the antibiotic silver ions and protecting structural integrity under high-temperature sintering, and in addition, due to a photocatalysis function of nanometer titania, antibiotic effect can be realized through photocatalysis after the silver ions are dissolved and volatilized completely. The prepared long-acting composite antibiotic ceramic is good in antibiotic effect and has long-acting antibiotic efficiency, the antibiotic rate is over 98%, and antibiotic effect remains unchanged after long-time use.