Western Henan, located in the confederation of loess plateau and the Huang-Huai-Hai Plain, is a typical dryland winter wheat production area in Henan. In this region, the lack of precipitation and the mismatch between the precipitation and water requirement of winter wheat growth is the most important limiting factor for yield formation in winter wheat. Therefore, it is of great significance to adopt effective agronomic measures for accumulating the precipitation in summer season, and therefore improve grain yield in winter wheat. Previous studies have been shown that optimizing surface management in summer fallow season could improve soil moisture and wheat grain yield. However, the effects of surface management in summer fallow season on the photosynthetic characteristics in flag leaves and grain yield formation in winter wheat is still limited. Field experiment was carried out in Meiyao Village (E111°71′, N34°47′), Luoning County, Henan from July 2019 to June 2021. In the present experiment, five surface management were set up in the summer fallow season: Conventional tillage (CT), Deep tillage (PT), No-tillage with straw mulching (NT), Subsoiling with straw mulching (SM), and subsoiling concurrently furrowing with straw mulching (SFM). The ploughing operation in CT was ploughed (15 cm depth) in late July using a small walking tractor according to local farmers practice. The ploughing operation in PT was board ploughed in early August with depth of 30 cm using a turnover plow. There is no tilled in NT, and the straw is evenly covered on the surface. The subsoiling operation in SM was using ditch type subsoiler with a spacing of 35 cm after the first rainfall after the previous wheat harvest. The subsoiling operation in SFM is the same as SM, after subsoiling, furrowing was carried out in the deep pine belt with ditch width 10 cm, ridge height 20 cm, ridge width 25 cm. In order to facilitate field farming operations, the regional design was adopted, and each region was designated with 3 sampling areas with a representative area of 5 m×7 m at the seedling stage, and in each sampling area, the portable photosynthetic assay system Li-6400XT (produced by THE AMERICAN LICENSE company) was used to determine the flag leaf net photosynthetic rate (Pn), stomatal conductivity (Gs), transpiration rate (Tr), intercellular carbon dioxide concentration (Ci), instantaneous water use efficiency (IWUE) during the grain filling stage, and the grain yield at maturity was determined. Different surface management in summer fallow season had some significant effects on the photosynthetic characteristics in flag leaves during the middle of grain filling stage and the grain yield. Compared with CT, the Pn in flag leaves was significantly increased by 48.88%, 125.23% and 80.37% respectively under PT, SM, SFM. The flag leaf Gs under SM and SFM were increased significantly by 92.22% and 126.67%, as well as the flag leaf Tr by 58.97% and 77.15%. Instantaneous water use efficiency (IWUE) in flag leaves under SM was increased significantly by 41.84%, compared with CT. Among different surface managements, the intercellular carbon dioxide concentration (Ci) in flag leaves was no significantly different. Grain yield was increased by 0.23%, 5.56%, 22.71% and 30.17% respectively under PT, NT, SM, SFM, compared with CT. Therefore, SFM could significantly improve the flag leaf Pn, Gs, Tr and maintain the good flag leaf photosynthetic characteristics during the middle grain filling stage, thereby increasing the grain yield in wheat, which is a suitable summer surface management method for winter wheat production in the dryland area of western Henan.