A high-performance melatonin sensing platform based on carbon nanofibers arrays decorated with FeCo alloys is described. A kind of carbon nanofiber based on FeCo bimetallic alloy was prepared by electrospinning. The synergistic effect of FeCo enhanced the electrocatalytic property and electron transfer ability of the materials. In addition, on the basis of the composite material, we study the electrooxidation behavior of melatonin and its reaction mechanism, and build a rapid succession of quantitative detection of melatonin electrochemical sensor with the detection range of 0.08-400 um and a detection limit as 2.7 nm. Compared to previous reports, this melatonin sensor possesses excellent properties and wide detection range.