[Objective] The study aimed to investigate the effects of silicon on physiology and biochemistry of Dendrobium moniliforme plantlets under low temperature stress.[Method] By using Dendrobium moniliforme as the experimental material, different concentrations of Na2SiO3 (0, 0.2, 0.4, 0.6, 0.8, 1.0, 5.0 and 10.0 mmol/L) was added to the basic medium[1/2MS+6-BA (0.1 mg/L)+NAA (1 mg/L)+agar (7.2 g/L)+sucrose (30 g/L)] for tissue culture; after hardening and transplanting, Dendrobium moniliforme plantlets were treated under low temperature stress at 4 ℃ for 0, 24 and 48 h, in order to investigate the physiological response of Dendrobium moniliforme leaves to different concentrations of Na2SiO3.[Result] Under low temperature stress at 4 ℃, Dendrobium moniliforme leaves have certain osmotic regulation ability, and the three osmotic regulation substances show different variation trends at different stages. Appropriate concentration of Na2SiO3 can increase the contents of free proline, soluble sugar and soluble protein to varying degrees, reduce MDA content and further improve the cold resistance of Dendrobium moniliforme plantlets. The order of the effects of Na2SiO3 on various physiological indicators is: free proline>MDA>soluble sugar (or soluble protein). According to the correlation analysis among various physiological indicators, free proline, soluble sugar, soluble protein and MDA contents can all be used as reference indicators to identify the cold resistance of Dendrobium moniliforme.[Conclusion] The addition of Na2SiO3 (0.4 mmol/L) can moderately decrease the thermal energy for normal growth of Dendrobium moniliforme, which is conducive to reducing the cost of cultivation. [Objective] The study aimed to investigate the effects of silicon on physiology and biochemistry of Dendrobium moniliforme plantlets under low temperature stress. [Method] By using Dendrobium moniliforme as the experimental material, different concentrations of Na2SiO3 (0, 0.2, 0.4, 0.6, 0.8 mg / L, 1.0 mg / L and 10.0 mmol / L) was added to the basic medium [1/2 MS + 6- BA (0.1 mg / L) + NAA 30 g / L)] for tissue culture; after hardening and transplanting, Dendrobium moniliforme plantlets were treated under low temperature stress at 4 ° C for 0, 24 and 48 h, in order to investigate the physiological response of Dendrobium moniliforme leaves to different concentrations of Na2SiO3 [Result] Under low temperature stress at 4 ° C, Dendrobium moniliforme leaves have certain osmotic regulation ability, and the three osmotic regulation substances show different variation trends at different stages. Appropriate concentration of Na2SiO3 can increase the contents of free proline, solubilizers The order of the effects of Na2SiO3 on various physiological indicators is: proline> MDA> soluble sugar (or soluble protein). According to to the correlation analysis among various physiological indicators, free proline, soluble sugar, soluble protein and MDA contents can all be used as reference indicators to identify the cold resistance of Dendrobium moniliforme. [Conclusion] The addition of Na2SiO3 (0.4 mmol / L) can moderately decrease the thermal energy for normal growth of Dendrobium moniliforme, which is conducive to reducing the cost of cultivation.