The fast chlorophyll fluorescence induction curve contains rich information of photosynthesis.It can reflect various information of vegetation,such as,the survival status,the pathological condition and the physiology trends under the stress state.Through the acquisition of algae fluorescence and induced optical signal,the fast phase of chlorophyll fluorescence kinetics curve was fitted.Based on least square fitting method,we introduced adaptive minimum error approaching method for fast multivariate nonlinear regression fitting toward chlorophyll fluorescence kinetics curve.We realized Fo (fixedfluorescent),Fm (maximum fluorescence yield),σPSII (PSII functional absorption cross section) details parameters inversion and the photosynthetic parameters inversion of Chlorella pyrenoidosa.And we also studied physiological variation of Chlorella pyrenoidosa under the stress of Cu2+.