In this study, 2yearold Malus halliana Koehne were treated under salt stress (NaCl), saltalkali mixed stress (NaCl+NaHCO₃, 1∶1), alkali stress (NaHCO₃) and water as the control (CK). The changes of pigment content, photosynthetic parameters, chlorophyll fluorescence parameters, relative conductivity and osmotic adjustment substance content of Malus halliana Koehne leaves at different time points were determined by pot experiment to explore the physiological response characteristics of M. halliana Koehne under different salinealkali stress. The results suggested that: (1) under three salinealkali stress conditions, the synthesis of photosynthetic pigments (chlorophyll a, b and carotenoids) in leaves of M. halliana Koehne was inhibited with the prolongation of stress time, and the decrease was most obvious under alkali stress. After 40 days of stress, Chl a, Chl b and Car decreased by 67.18%, 68.90% and 64.67%, respectively. (2) The net photosynthetic rate (P_n), stomatal conductance (G_s) and transpiration rate (T_r) of M. halliana Koehne leaves were inhibited under three salinealkali stresses and significantly lower than CK, while the intercellular CO₂ concentration (C_i) under alkali and salinealkali treatments increased by 137.13% and 77.66% respectively after 20 d of stress, and decreased by 56.82% and 51.89% respectively after 40 d of stress. (3) With the extension of stress time, the actual photochemistry efficiency (Φ_PSⅡ), maximum fluorescence (F_m), photochemical quenching coefficient (qP) and maximum photochemical efficiency (F_v/F_m) of M. halliana Koehne leaves were inhibited under three salinealkali stresses. However, the initial fluorescence (F₀) and the nonphotochemical quenching coefficient (qN) of salt treatment and saltalkali mixed treatment showed an increasing trend under alkali stress, and increased by 60.98%, 90.70%, 99.15% respectively after 40 days of stress compared with CK. (4) Compared with CK, the relative electrical conductivity (REC) of leaves in salt, alkali and saltalkali treatments increased by 9.39%, 35.07% and 29.32% respectively after 40 days of stress. At the same time, soluble sugar (SS), proline (Pro), organic acid (OA) of leaves were significantly higher than that of CK after 40 days of stress, and OA was more sensitive to saltalkali mixed treatment. The amount was significantly higher than that of salt treatment and alkali treatment. (5) The growth and photosynthesis of M. halliana Koehne under three stresses were inhibited by alkali treatment > saltalkali mixed treatment > Salt treatment. It was found that the photosynthesis of M. halliana Koehne was significantly inhibited by three salinealkali stresses, and the effect of alkali stress was greater, but it could cope with the stress by osmotic regulators, effectively alleviate the damage of salinealkali stress and enhance its saltalkali tolerance.