The heat value of food processing sludge is similar to that of bituminous coal, thus is suitable as biofuel; however, the problem of incinerated ash disposal after combustion should be address. This study evaluated the applicability of food processing sludge-derived fuel incinerated ash (FA) to pozzolanic material and soil improvement, and proposed reuse strategies. When applied to pozzolanic material, the addition of FA reduced the hydration heat of fresh incinerated ash cement paste (FACP) significantly (85.96~91.23%), and prolonged the initial setting times (87.88~134.85%) and final setting times (87.88~134.85%) of FACP significantly. When the FA addition was 10% and 20% respectively, the pozzolanic strength activity index (SAI) was greater than 75% until the hardened FACP was cured for 28 days and 90 days respectively. When applied in soil improvement, the final seed germination of Chinese cabbage and water spinach in the original soil (ash content 0%) and improved soil (ash content 20%) was 98% and 90% respectively. There was no significant effect on the growth rate of Chinese cabbage and water spinach.