Two neutral salts, NaCl and Na₂SO₄, and two alkali salts, Na₂CO₃ and NaHCO₃, were selected and mixed in various ratios according to the varying ranges of salinity and pH in the natural soil, and the response of Bassia dasyphylla seedlings to salt-alkaline stress was determined. The photosynthetic pigment content, photosynthetic gas exchange parameters, and chlorophyll fluorescence parameters were determined. The results showed 30 different salt-alkaline ecological conditions, which included salinity of 50-250 mmol/L and pH values of 7.10-10.19. The chlorophyll a (Chl a), chlorophyll b (Chl b), and carotenoids (Caro) contents, net photosynthetic rate (P_n), stomatal conductance (G_s), intercellular CO₂ mole fractions (C_i), transpiration rate (T_r), PSⅡ potential efficiency (F_v/F₀), maximal photochemical efficiency (F_v/F_m), PSⅡ actual quantum yield (ΦPSⅡ), apparent electron-transfer rate (ETR), and photochemical quenching (qP) indexes of the treatment group were significantly lower than that of the control group; both reduced with increasing salinity and pH; and were significantly different (P<0.05) from the negative control group. Steady state fluorescence (F_s) result indicates the variation trendency of "M-type" with increasing salinity and pH, which is firstly increased and then decreased, followed the similar trendency again. Water use efficiency (WUE) and non-photochemical quenching (NPQ) showed irregular change with increasing salinity and pH. The correlation coefficient between salt ions and the photosynthetic characteristics showed that the rejection capability of sodium salts was Na₂CO₃ > NaHCO₃ > NaCl > Na₂SO₄ in the photosynthetic pigment content index and gas exchange parameters. The effect of salt ions and chlorophyll fluorescence parameters was comparatively complex. This study suggests that salt-alkaline environments inhibited the photosynthetic system of B. dasyphylla, and negatively affected several physiological responses.