In order to investigate the carbon sequestration and oxygen release capacity of typical plants in the Helan Mountain, the photosynthetic physiological indexes of 10 species of trees, shrubs and grasses were measured by using the portable Li-6400XT photosynthetic apparatus, and the daily carbon sequestration and oxygen release capacity were analyzed. The results showed that:(1) The leaf area, leaf dry weight and leaf area index of Picea crassifolia were significantly higher than those of other plants. The specific leaf area of Carex muliensis was the highest, and showed a rank of herb > shrub > tree. The average daily net photosynthetic rate of Thermopsis lanceolata was the highest, and there was no significant difference between trees, shrubs and grasses. (2) The descending order of daily carbon sequestration and oxygen release capacity per unit leaf area was T. lanceolata, Ulmus glaucescens, Populus davidiana, Cotoneaster hissaricus, Agropyron cristatum, Pinus tabuliformis, Lonicera microphylla, Berberis thunbergii, P. crassifolia, C. muliensis. The descending order of daily carbon sequestration and oxygen release capacity of unit crown width was P. davidiana, P. crassifolia, U. glaucescens, P. tabuliformis, C. hissaricus, B. thunbergii, L. microphylla. The descending order of daily carbon sequestration and oxygen release capacity of a single plant was P. crassifolia, P. davidiana, P. tabuliformis, U. glaucescens, B. thunbergii, C. hissaricus, L. microphylla, T. lanceolata, A. cristatum. The daily carbon sequestration and oxygen release capacity of the four typical stand trees were in a rank of P. crassifolia forest, mixed forest, P. tabuliformis forest, U. glaucescens forest. (3) According to cluster analysis results, the carbon sequestration and oxygen release capacity on the per leaf area of trees (4 species) and shrubs (3 species) were divided into two levels, and herbs (3 species) were divided into three levels, which on the projection area scale of unit crown width of trees (4 species) and shrubs (3 species) were divided into three levels. However, the tree (4 species), shrub (3 species) and herb (2 species) were divided into two levels according to the single plant scale, and on the scale of unit land area of different forest species, four typical forests are divided into two levels. (4) There was no significant correlation between the daily carbon sequestration and oxygen release per unit leaf area of plants and the plant morphological indicators. The daily carbon sequestration and oxygen release per unit canopy projection area was significantly positively correlated with the leaf area index. Moreover, we observed that the daily carbon sequestration and oxygen release per plant was significantly positively correlated with plant height, diameter at breast height and leaf area index. The daily carbon sequestration and oxygen release per unit forest area was significantly positive correlation with stand density. In conclusion, both P. crassifolia and P. davidiana had high carbon sequestration and oxygen release capacity in different scales. In the ecological restoration process of the Helan Mountain in the future, the two species of trees should be given priority consideration, and shrubs and herbs with high carbon sequestration and oxygen release capacity, such as C. hissaricus, should be added to achieve the maximum ecological benefits.