Objective To find out the microalgae species in the spring water and the pollution route in the production process of drinking spring water. Methods 42 samples were collected from the workshop, the spring source, the product line and the repeated barrels in a water plant. The microalgae were examined by microscope, CCD imaging system and scanning electron microscope. Results 18 microalgae species were detected from the 42 samples including 4 species in Cyanophyta, 9 in Chlorophyta, 4 in Bacillariophyta and 1 in Euglenophyta. The dominant species occurred in samples of the floor around the workshop and the floor beside the wellspring bump were Achnanthes biasolettiana and Cymbella affinis, in the spring source were Chlamydomonas sp. and Ulothrix tenerrima, in the spring water barrel was Scenedesmus obliquus. Chlorella vulgaris was detected in all processes before the super-filter,and after filtered, no microalgae was detected, but in the product water, Chlorella vulgaris was still detected after enriched culture. Conclusion Usually, the microalgae polluted drinking spring water products is mainly Chlorella vulgaris and the pollution route is reusing of barrels.