Mycotoxin, common in agricultural products, is a small secondary metabolite with strong toxicity. Fumonisin B1 (FB1) is the most common and the most toxic. Establishing a rapid detection method is important for preventing and controlling FB1 pollution. This study prepared carbon dots (CDs) from 2,2'-dithiosalicylic acid (DTSA). Tetramethylbenzidine (TMB) can be catalyzed to produce fluorescence by CDs, while FB1 can adhere to the surface of CDs, decreasing fluorescence. Aptamer F10 of FB1 combines with FB1 attached to the surface of CDs to restore the catalytic ability of CDs and increase the fluorescence value. This method has good linearity in the FB1 concentration range from 0 to 1.0 μg mL-1. The standard curve was Y = -0.2512x + 661.4, R2 = 0.9903, the limit of detection (LOD) was 17.67 ng mL-1 and limit of quantitation (LOQ) was 53.55 ng mL-1. The recovery of the corn sample was 89.83-98.62%, and the detection time was 30 min.