Salt stress is one of the major environmental factors affecting plants; it causes many changes in plant metabolism, such as decreasing the capacity and efficiency of photosynthesis and inhibiting growth. Salt stress also changes leaf cell structure. Therefore, plant growth, photosynthesis, and leaf cell structure are often used as indicators of salt stress injury in plants. In response to salt stress, plants have evolved diverse mechanisms that can mitigate the effects of stress and lead to improved plant tolerance. In this study, 1-year-old potted seedlings of ‘Yinghong’ grape were used to examine their changes in growth, photosynthetic characteristics, and leaf cell structure under different levels of salt stress, ranging from NaCl concentrations of 0% to 0.8%. The goal of this experiment was to provide reference information for grape cultivation in salty soils. Because of the complexity of the soil composition in the natural state, the actual salt concentration of soil is difficult to control. Thus, to investigate the responses of grape seedlings to specific and precise salt concentration conditions, a total of 100 potted seedlings were divided into five groups, and 20 seedlings each were placed into Hoagland hydroponic culture with one of five salt concentrations, specifically 0%, 0.2%, 0.4%, 0.6%, and 0.8% NaCl. The chlorophyll content, gas exchange parameters, and chlorophyll fluorescence parameters of the grape seedlings were measured every 15 days, and the characteristics of the growth and leaf cell structure were measured after 45 days. In this study, the LA-S plant image analysis system was used to measure the growth traits, such as the length, average diameter, surface area, volume of the root system, and leaf area. Chlorophyll content was measured with a SPAD-502+PLUS chlorophyll meter. The GFS-3000 portable photosynthesis system was used to measure gas exchange parameters, such as the net photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (Tr), and intercellular CO₂ concentration (Ci). The JUNIOR-PAM chlorophyll fluorometer was employed to measure chlorophyll fluorescence parameters, such as the maximum photochemical efficiency of photosystem Ⅱ (PSⅡ) (Fv/Fm), PSⅡ potential activity (Fv/Fo), electron transport rate (ETR), photochemical quenching (qP), and non-photochemical quenching (qN). Finally, leaf cell microstructure and palisade tissue chloroplast ultrastructure were observed with an OLYMPUS optical microscope and a HITACHI-7650 transmission electron microscope. Grape seedlings in the low salt treatments (0.2% and 0.4% NaCl) grew normally, and the chlorophyll content, leaf cell structure, gas exchange parameters, and chlorophyll fluorescence parameters were not significantly different in these treatments from those of the control (0% NaCl). At higher NaCl concentrations (0.6% and 0.8% NaCl), plant growth was significantly constrained. The epidermis cells, palisade tissue, and spongy tissue in the leaves were thicker, the intercellular space within the palisade tissue and spongy tissue was larger, the chloroplasts became swollen, and the numbers and sizes of starch grains and plastoglobules were greater compared with the control. In addition, the chlorophyll content, Pn, Gs, Tr, Ci, Fv/Fm, Fv/Fo, ETR, qP, and thickness ratio of the palisade/spongy tissue were lower and qN was higher relative to the control. In particular, compared with the control, significant changes in plant growth status, chlorophyll content, leaf cell structure, gas exchange parameters, and chlorophyll fluorescence parameters were observed under high salt stress (0.8% NaCl). Therefore, 1-year-old potted seedlings of grape ‘Yinghong’ could grow normally under low salinity stress(NaCl ≤ 0.4%).