The simulation of photosynthetic product distribution and transfer is an important part of crop growth simulation. Based on the irrigation experiment data (high water treatment T1 and zero water treatment T2) of spring maize of three years (2018, 2019 and 2020) at Wenyuhe Experimental Station in Shanxi Province, the distribution methods of photosynthetic products (distribution coefficient method and distribution index method) were adopted for the simulation study. The results showed that the simulated and measured R2 values of stem, leaf and spike of the two methods were all above 0.9 in terms of fitting accuracy, and the simulated precision of spike was the highest (R2 was above 0.95) . Water stress could decrease the stem distribution index, increase the leaf and spike distribution index, and it had the greatest influence on the spike distribution index. Water stress mainly influences the distribution coefficient by affecting the growth correlation indices (stem-leaf ratio, spike-stem ratio and root-shoot ratio). It was found that the simulation effect of spike-stem ratio was the best (the simulated value and the measured value of R2 were 0.882) , the water stress index of stem-leaf ratio was -0.130, which indicated that the water stress would lead to the decrease of stem-leaf ratio. The water stress indexes of spike-stem ratio and root-shoot ratio were 0.248 and 0.143, indicating that water stress could increase spike-stem ratio and root-shoot ratio. Water stress had little effect on the distribution coefficient of stem, leaf and root at early stage, but at later stage, water stress increased the distribution coefficient of stem, leaf and root, and decreased the distribution coefficient of spike. Water stress reduced the transfer rate of vegetative organs. On the whole, the fitting accuracy of the two methods are very close to each other, but the distribution coefficient simulation method is more close to the actual situation, which shows that the mechanism of the distribution coefficient method is more plausible.