The application discloses an interplanting method for potato and garlic in organic sorghum land comprising following steps: potato variety selection and potato seed preparation; garlic variety selection and garlic seed preparation; organic sorghum straw harvest and plant ash preparation; soil preparation, reapplying base fertilizer and excavating drainage ditch; the row ratio of potato to garlic; planting potato; ridging for potato; interplanting garlic; harvesting potato and weeding, fertilizing and earthing for garlic; later-period management; harvesting young garlic shoot; harvesting garlic. By means of the method, the target of maintaining land with land is achieved; the Hongyingzi organic sorghum land system energy balance is kept; the soil organic matter content is greatly increased; soil is effectively fertilized; the yield of organic sorghum is increased without increasing other production cost.