The present invention provides a short-circuit unit comprising: a plurality of signal lines divided into a plurality of groups, each group comprising multiple signal lines, and the multiple signal lines in a same group are not adjacent to each other; a plurality of short-circuit lines, each group of the signal lines correspond to one short-circuit line, and the short-circuit line electrically connects all of the signal lines in the group corresponding to the short-circuit line, the plurality of short-circuit lines are disposed in different layers and the short-circuit lines in different layers are insulated from each other. The present invention also provides an array substrate. In the short-circuit unit of the present invention, the short-circuit lines are disposed in different layers. Compared to the existing solutions in which the short-circuit lines are provided in a same layer, the width occupied by the short-circuit unit of the present invention is smaller.