TECHNOLOGY FOCUS - BIOLOGY - Preferred Method: The mixed solution is obtained by diluting the urea solution using water, where the total nitrogen concentration variation range of the mixed solution is controlled to 28.36-38.10 mg/l, the ammonia nitrogen variation range is controlled to 16.17-358.71 mg/l, the total phosphate variation range is controlled to 1.08-25.71 mg/l, the potassium vibration range is controlled to 4.39-104.76 mg/l, the pH value of vibration range is controlled to 7.12-8.57 and entering the mixed solution into the algae culture device when it meets the above standards, where the algae in the oil algae culture device comprises brown grape alga, Chlorella, Nannochloropsis algae, Chlamydomonas reinhardtii, Phaeodactylum tricornutum and/or equilateral golden algae. The oil algae is cultured by firstly, discharging and obtaining 80-95% of the algae urea mixed solution from the culture device when the algae grows to peak, keeping 5-10% of algae urea mixed solution in the culture device and taking it to the next cycle of algae source, adding the urea mixed solution into the oil algae culture device, culturing the mixture for 20-60 days, where the urea solution does not need to be delivered to the device in the course of culturing process, after finishing the culture when the algae grows to peak and repeatedly performing the next cycle of culture. The oil algae culture method is performed by a dynamic culture model, where the dynamic culture model continuously delivers the urea solution to the culture device under a certain flow speed and absorbing the mixed solution for 20-60 days. Preferred Components: The oil algae culture device is provided at the top of the residential area or the residential wall external lighting good place. The container in the device is made of translucent material. The translucent container of the oil algae is provided with a temperature regulating device with a temperature of 10-35 degrees C. The oil algae device is provided with a light intensity sensing probe, a lighting device, a sterilizing device, an aeration device and a stirring device.