At the need of ecological restoration of subcritical flow such as polluted pool, the characteristics, purification principle and operation monitoring indexes of the carbon fiber artificial plants technology are presented. And the current pollution condition of Zhaoyuan pool is analyzed. By the treatment of the microorganisms lived at the artificial plants, the ecology of Zhaoyuan pool is to be restored. An in-situ experiment was conducted to determine optimal running density of the artificial plants. As a result, the optimal running density is 16/m². At this situation, the removal rate of CODcr , NH3-N, TN, TP were 69.16%, 81.06%, 72.92%, and 47.36% respectively. Because of the high efficiency and having no undesirable impact on the ornamental value of pools, the technology of carbon fiber artificial plants can be widely used in the future.