A detection chip, a using method for the same, and a reaction system. The detection chip includes a first substrate, a micro-cavity defining layer, and a heating electrode. The micro-cavity defining layer is on the first substrate and defines a plurality of micro-reaction chambers. The heating electrode is on the first substrate and is closer to the first substrate than the micro-cavity defining layer, and is configured to heat a plurality of micro-reaction chambers. The orthographic projection of the plurality of micro-reaction chambers on the first substrate is within the orthographic projection of the heating electrode on the first substrate.