In order to explore the response mechanism of photosynthesis of spring wheat leaves to climate change in northern Ningxia, the effects of warming on the growth of spring wheat in arid and semi-arid regions were further clarified. The effects of elevated temperature on leaf area, photosynthetic pigment content, photosynthetic characteristics, chlorophyll fluorescence parameters, and dry weight of spring wheat during the growth period in northern Ningxia were tested using automatic control infrared radiator for simulating climate change in the field. The method was based on the temperature of the spring wheat canopy temperature without treatment, and different temperature gradients were set (CK:0℃, T1:0.5℃, T2:1℃, T3:1.5℃, and T4:2.0℃). The results showed that leaf area, chlorophyll content, Pn (net photosynthetic rate), and WUE (leaf water use efficiency) of spring wheat had an upward trend when the temperature increased by 0.5℃ during seedling-jointing stage. The above indices indicated a downward trend when the temperature increased by 1.0-2.0℃, while Ls (stomatal limitation value) showed an upward trend and Ci (intercellular CO₂ concentration) showed a downward trend, indicating that the decrease of Pn in leaves was mainly caused by the decrease of chlorophyll content and stomatal limitation. However, after the jointing stage, the leaf area, chlorophyll content, Pn, WUE, and Ls were decreased when increasing temperature, while Ci increased, which indicating that the decrease of leaf Pn was mainly caused by a decrease in chlorophyll and non-stomatal limitation. Chlorophyll fluorescence parameters showed that spring wheat was resistant to temperature rise before jointing stage, and could cope with the warming stress to protect itself in the form of heat dissipation. After the jointing stage, the photosystem II reaction center of spring wheat leaves was reversibly inactivated by temperature stress, and the photosynthetic apparatus was destroyed. In addition, the change trend of dry weight of spring wheat was basically consistent with that of leaf area and other indicators. The yield and yield components, spikelet number, grains number per spike, and 1000-grain weight decreased significantly with rising temperature. When 0.5℃ rising before jointing stage, it was beneficial to increase the potential activity of leaf photosystem II, increase leaf resistance, promote photosynthesis, and eventually increase photosynthetic product. If the temperature gradient is too large or the heating time is too long, spring wheat will be subjected to high temperature stress, which leads to the reduction of the original light energy capture and electron transfer efficiency of the leaf photosystem II, and the photosynthetic mechanism is damaged. Finally, the values of Pn and WUE in the leaves of spring wheat decreased, the accumulation of photosynthetic products and the yield decreased.