The invention relates to the field of microalga culture, specifically to an airlift photobioreactor for realizing a microalga flash effect. The reactor comprises a tank body (1), a guide cylinder (2), a gas distributor (3), a top cap (5) and internal light sources, which are segment-wise luminescent rod light sources (6). Being parallel to the flow direction of a microalga culture solution, the rod light sources (6) are composed of continuously alternating luminescent segments (7) and non-luminescent segments (8), and are used for forming continuously alternating light zones and dark zones around the rod light sources. The invention has the advantages that: the flash effect of algal cells can be brought into full play, the light energy utilization of mass microalga culture can be improved, liquids can be well mixed, the strength of gas-liquid mass transfer is high, and the shear force is low.