For an algebraically closed field $K$ with $\mathrm{ch}(K)\neq 2$, let $\mathcal{O}M(1, SO(n,K))$ denote the moduli space of holomorphic bundles on $\mathbb{P}^{2}$ with the structure group $SO(n,K)$ and half the first Pontryagin index being equal to 1, each of which is trivial on a fixed line $l_{\infty}$ and has a fixed holomorphic trivialization there. In this paper we determine the Chow ring of $\mathcal{O}M(1, SO(n,K))$.