The invention is an algal culture system and a gas mixing device thereof.The algal culture system comprises a culture tank unit.Having a cylindrical groove；A gas pipe extends from the outside of the tank into the inside of the tank；A gas mixing device is connected to the air pipe.It is used to mix oxygen and carbon dioxide and then inject them into the aquaculture water through the airway；And a light source device,Having a cylindrical light-emitting unit,The luminous unit is located in the center of the tank.The light source device has a control circuit.To control the wavelength and intensity of the light emitted by the light-emitting unit,Necessary for the growth of algae suitable for cultivation in the tank；With the above technologies,The creation can control the environment in the algal culture tank, which is suitable for algal growth conditions.In order to improve the efficiency and quality stability of algae culture.本創作為一種藻類養殖系統及其氣體混合裝置，其中該藻類養殖系統包括：一養殖槽單元，具有一圓筒狀的槽體；一導氣管從該槽體的外側伸入於該槽體內部；一氣體混合裝置連接於該導氣管，用以將氧氣及二氧化碳混合後再經由該導氣管注入於養殖水中；及一光源裝置，具有一圓柱狀的發光單元，該發光單元設於該槽體的中心，該光源裝置具有一控制電路，用以控制該發光單元發出光線的波長及強度，以適合於該養殖槽內培養的藻類生長所需；藉由以上技術，本創作能夠控制藻類養殖槽內環境適合於藻類生長條件，以提高藻類養殖效率及品質穩定性。
