Based on the model of algae fluorescence yield and with the fluorescence saturation parameter E_σ as the judgment standard of saturated excitation light intensity, we proposed a self-adaptive method of excitation light intensity to accurately acquire the photosynthetic fluorescence parameters of different species of algae. The results show that with the self-adaptive method, the saturated excitation light intensity could be quickly and stably obtained in the seven species of algae, and the relative standard deviations (RSDs) of the adjustment results were all smaller than 2.5%. Furthermore, the effective light absorption cross-sections σ_PSII of the seven species of algae were measured by the tunable pulse laser induced fluorescence (TPLIF) technique based on the self-adaptive method, and the difference in the σ_PSII of different species of algae was analyzed. Finally, we measured the Chlorella samples at different growth stages through the TPLIF technique and recorded their fluorescence parameter F_v/F_m and relevant variation trend. It turns out that the recorded results are consistent with the measurement results of the photosynthetic activity analyzer Fast-Ocean, with the correlation coefficient being 0.9939. In conclusion, this study provides an effective way of saturation excitation for accurately measuring the photosynthetic fluorescence parameters of different species of algae at different growth stages (with obvious differences in growth status).