Let \(\mathfrak {g}\) be an affine Lie algebra with index set \(\varvec{I}\) = {0, 1, 2, \(\ldots , \varvec{n}\}\) . It is conjectured that for each Dynkin node \(\varvec{k} \in \varvec{I} \setminus \{{\textbf {0}}\}\) the affine Lie algebra \(\mathfrak {g}\) has a positive geometric crystal. In this paper, we construct a positive geometric crystal for the affine Lie algebra \(\varvec{D}_{\textbf {7}}^{{\textbf {(1)}}}\) corresponding to the Dynkin spin node \(\varvec{k}= {\textbf {7}}\) .