低差分置换是对称密码算法的重要组件,最近屈等先后提出了优先函数、优先布尔函数的概念,并用之构造4-差分置换.构造了一些具有较少项数的优先布尔函数,将交换法中的布尔函数推广为F_(2~n)到F_4的映射,进一步研究了广义的交换构造,构造了三类新的4-差分置换,并计算了它们的非线性度. Low differential replacement is an important component of the symmetric cryptography algorithm. Recently, Qu et al. Proposed the concept of priority function and prioritized Boolean function, and constructed the 4-differential permutation. Some prioritized boolean functions with fewer number of terms are constructed, The Boolean functions are generalized as F_ (2 ~ n) to F_4 maps. The generalized exchange structures are further studied. Three new types of 4-differential permutations are constructed and their nonlinearities are calculated.