Abstract:With white light at 54 μmol/（m2·s）as the control，this study analyzed the effects of different blue light intensities [18，36，54，72 μmol/（m2·s）] on the photochemical activity and pigment accumulation of Haematococcus pluvialis on the basis of 54 μmol/（m2·s）white light.By measuring the cell density，chlorophyll and astaxanthin content，as well as chlorophyll fluorescence parameters of H.pluvialis，the study investigated the growth status and changes in astaxanthin content during light stress.The results showed that the inhibitory effect on H.pluvialis was most significant under mixed blue light at 36 μmol/（m2·s）.The maximum light energy conversion efficiency，effective light energy conversion efficiency，and apparent electron transfer rate parameters of photosystem II（PSII）in the blue light experimental group were generally higher than those in the control group，indicating that the photosynthetic structure and function of H.pluvialis were affected by light damage，and the plant produced a self-protective mechanism.Among the tested light intensities，blue light at 54 μmol/（m2·s）was found to be the most suitable mixed light intensity for H.pluvialis to accumulate astaxanthin.