Abstract: In order to explore the physiological and ecological adaptability of harmful periphytic algae in water conveyance open channels, a small runway pool was used indoors to simulate the environment. Specifically, periphytic algae (Laspinema sp. APE171) were selected. The chlorophyll a content and chlorophyll fluorescence parameters of Laspinema sp. APE171 were selected for examination. The study assessed the chlorophyll a content and chlorophyll fluorescence parameters of Laspinema sp. APE171 under different environmental conditions such as flow rate, light intensity, UV-A intensity, and turbidity. Furthermore, distinctions in the physiological state of Laspinema sp. APE171 in the water-air interface and benthic habitats were compared. The results showed that when the flow rate V > 0.23 m/s, the growth of Laspinema sp. APE171 was inhibited in the water-air interface habitat. Moreover, UV-A intensity at 440 μW/m² induced stress on the photosynthesis of Laspinema sp. APE171 in water-air interface habitat. Additionally, when the turbidity was 100 NUT, the photosynthetic activity of Laspinema sp. APE171 in the water-air interface habitat was the lowest, and Laspinema sp. APE171 was more sensitive to changes of environmental factors in the water-air interface habitat. Therefore, the effects of flow velocity, UV-A intensity, and turbidity on cyanobacterial growth in different habitats necessitate thorough consideration in the monitoring and management strategies aimed at controlling Laspinema sp. in open water conveyance channels.