The regular graph of the space of \(n \times m\) matrices over a field \(\mathbb {F}\) is defined as the undirected graph whose vertices are matrices of rank \(\min (n, m)\) , and distinct matrices A and B are connected by an edge if and only if \(\text {rk}(A + B) < \min (n,m)\) . In this paper, for \(|\mathbb {F}| > 4\) and \(m, n \ge 2\) , all additive automorphisms of the regular graphs are characterized. Furthermore, it is proved that any automorphism of the regular graph preserves the rank distance \(d(A, B) = \text {rk}(A - B)\) . Bibliography: 11 titles.