Rainfall is a crucial determinant influencing the growth and development of desert plants as well as the formation of plant communities in arid and semi-arid regions. In order to investigate the varying responses of desert plants to rainfall changes across different growth seasons, this study focuses on Artemisia ordosica, a representative desert shrub species in China's semi-arid regions. Using artificial rainfall manipulation, six rainfall levels were established: 70%reduce, 50%reduce, 30%reduce, natural rainfall (CK), 30% increase, and 50% increase. The study monitored changes in photosynthetic indicators, chlorophyll fluorescence indicators, nutrient indicators, and new aboveground biomass (NAB) of A. ordosica leaves across the germination and leaf development period, vigorous growth period, and flowering and fruiting period under these different rainfall levels. Additionally, the study explored the relationship between new aboveground biomass and the photosynthetic indicators, chlorophyll fluorescence indicators, and nutrient indicators of A. ordosica across the growth seasons.The results show that: (1) Rainfall treatment significantly affects the new aboveground biomass, photosynthetic indicators and chlorophyll fluorescence indicators and nutrient indicators of A. ordosica. With increasing rainfall, the new aboveground biomass, net photosynthetic rate(Pn), potential activity(Fv/Fo), maximum photoelectrochemical quantum yield(QY-max), photochemical quenching coefficient(qP), actual photochemical quantum efficiency(φPSII), and leaf carbon nitrogen ratio(C ∶ N) of A. ordosica significantly increased, while water use efficiency(WUE), non photochemical quenching coefficient(NPQ), leaf carbon phosphorus ratio(C ∶ P), and leaf nitrogen phosphorus ratio(N ∶ P) significantly decreased (P<0.05). (2) Variations in rainfall have distinct impacts on the photosynthetic indicators and new aboveground biomass of A. ordosica across the growing season (P<0.05). The germination and leaf development period is pivotal for biomass accumulation, exhibiting the highest sensitivity to rainfall fluctuations. In contrast, the biomass accumulation during the flowering and fruiting period is less responsive to variations in rainfall. (3) The correlation analysis between biomass and various physiological indicators across different growth seasons reveals that during the germination and leaf development period, plant biomass accumulation is influenced by water use efficiency and nutrient availability. In the vigorous growth period, there is a significant correlation with water use efficiency, nutrient environment, and fluorescence activity. However, in the flowering and fruiting period, the correlation between biomass accumulation and physiological parameters diminishes, suggesting a weaker growth regulatory capacity during this period. The findings from the study have enhanced our understanding of desert plant growth and vegetation stability, providing theoretical foundations for predicting and managing vegetation in the context of climate change.