The effect of U-shaped double stem pruning on the growth, photosynthetic characteristics and yield of pepper in winter was studied with "Ballem" as experimental material. The results showed that the growth and development of the root were enhanced obviously, and the chlorophyll content and net photosynthetic rate of leaves increased when the U-shaped pruning technique was used to keep double stem shape, and the root activity increased by 15.44% in the early growth stage. The chlorophyll contents of upper and lower leaves were 3.47% and 3.46%higher than control, respectively. The net photosynthetic rate was 1.58% and 7.92% higher than control, respectively. Yield of the total yield increased 993.69 kg/667 m², 7.34% compared with control.