The purpose of this study is to use snakehead fish pond sludge combined with agricultural by-products to produce organic fertilizer for growing spinach. The study included three main contents: (1) assessing the main characteristics affecting vegetable cultivation in the study area; (2) organic fertilizer production by mixing 30% sewage sludge with 70% organic materials such as peanut shells and coconut fiber; and (3) growing vegetables and evaluating the growth of vegetable plants by using organic fertilizer obtained from experiment 2 to grow vegetables according to five treatments combining inorganic fertilizer and organic fertilizer in the ratio: 100% inorganic fertilizer muscle (control), gradually reduced to 75, 50, 25, and 0%. The results showed that the highest vegetable yield was obtained in treatment three when using 50% inorganic fertilizer and 50% organic fertilizer. This discovery can be used for the cultivation of some other crops in agriculture. At the same time, the research makes a significant contribution to reducing the discharge of agricultural by-products into the natural environment.