基于控制理论中“黑箱”理论的基本思想,提出了直接采用土壤水瞬态运动模拟来求得吸水项的方法.利用所提出的估计方法求得了桃树的吸水强度;并用修正的吸水模型对吸水函数用回归分析方法进行了估计,得到了吸水场函数的连续表达式.结果表明这种表达方法具有高度的显著性,同时还说明该果园桃树根系在水平方向的分布可认为是均匀的.对模型进行的检验结果表明模型计算值与实际情况相符,说明这种方法是可行的. Based on the basic idea of ​​“black box” theory in control theory, this paper proposed a method to directly calculate the water absorption term by simulating the transient movement of soil water. The water absorption strength of peach tree was obtained by using the proposed estimation method. The water absorption function was estimated by regression analysis, and the continuous expression of water field function was obtained. The results showed that the expression was highly significant, and also showed that the horizontal distribution of peach root in the orchard could be considered as uniform The test result of the model shows that the calculated value of the model is consistent with the actual situation, which shows that this method is feasible.