The disclosure provides a quantum dot structure, a manufacturing method thereof, and a quantum dot light-emitting device. The quantum dot structure includes a core structure and a shell layer. The core structure includes a first metal element, at least one second metal element, and a non-metal element that bind through a chemical bond. The first metal element is a group III element, the non-metal element is a group V element, and the second metal element is a metal element different from the first metal element. In an inside-to-outside direction of the core structure, the content of the first metal element is in a descending order, the sum of content of the second metal element is in an ascending order, and the size of an optical band gap of the core structure is in the ascending order.