【Objective】The canopy structure of walnuts (Juglans spp.) is closely related to their growth, yield and quality. By using a digital canopy analyzer to collect canopy parameters and investigate the differences in canopy characteristics among walnut trees of different ages and their correlations with yield and quality, this study aims to provide a theoretical basis for the cultivation management and tree training of walnut trees.【Method】Using a digital plant canopy analyzer (HemiView), canopy images of J. sigillata cv. Yangpao trees at 10, 20, 30 and 40 years of age were collected in the early morning when there was no direct sunlight. The canopy images were analyzed using canopy image analysis software to obtain parameters such as total light transmittance,leaf area index (LAI), canopy light site coefficient, and intercepted radiation by the canopy for trees of different ages. After fruit maturation, individual trees were harvested to measure the fresh fruit weight, dry fruit weight, and major internal components of the fruits. Correlation analysis was performed on the canopy parameters, yield, and quality data.【Result】The leaf area index (LAI) of walnut trees showed similar trends across different ages,with a slight increase from May to July, a slight decrease from July to August, and a rapid decrease from August to October. This result is consistent with the phenological patterns of walnuts in the region, where leaf expansion is mostly completed by May, with only a few new shoots still growing, and new shoot growth ceases in July. The total canopy light transmittance and light site coefficient exhibited opposite trends to the LAI. The intercepted radiation by the canopy increased initially and then decreased. The yield per walnut tree increased with age, with fresh fruit yields per tree at 10, 20, 30 and 40 years of age being 3.39, 10.34, 33.00 and 54.73 kg, respectively. The fresh fruit weight, dry fruit weight, and nut dimensions (longitudinal, transverse, and thickness diameters) increased with age, while the thickness of the fruit husk decreased with age. The moisture content of nuts was around 34% and the shell thickness was around 1 mm for all ages, with no significant differences. The kernel extraction rate increased with age, ranging from 48.59% to 51.61%. The oil content of nuts was around 64%, and the protein content increased with age, ranging from 15.14% to 17.13%. The yield per tree, fresh fruit weight, and dry fruit weight were significantly positively correlated with the LAI and intercepted radiation. The thickness of the fruit husk was significantly negatively correlated with the LAI. The thickness of the nut shell was significantly positively correlated with the intercepted diffuse radiation. The kernel extraction rate was significantly positively correlated with the total intercepted radiation and direct radiation. The protein content of nuts was significantly positively correlated with the LAI.【Conclusion】Analyzing and understanding the dynamic changes in canopy parameters of walnut trees can provide reference for specific guidance on different age groups of pruning and tree body cultivation.