Abstract: This paper first presents conventional trellis for linear block codes and BCJR construction for conventional trellises.And a new way of constructing more minimal trellises for linear block codes is presented.It is proved that more minimal trellis can be constructed by the process of permuting the columns of parity check matrix from the well-known Bahl-Cocke-Jelinek-Raviv（BCJR） constructed conventional trellises.Furthermore，this paper gives main idea of parity check matrix permutation，algorithm’s description，main programming code and experiment conclusion.

Key words: linear block codes, minimal trellises, trellis complexity, parity check matrix permutation

摘要： 首先介绍线性分组码的传统网格和BCJR传统网格，然后给出一种新的降低线性分组码网格复杂度方法——校验矩阵置换法。该方法是通过置换校验矩阵列向量的适当位置，从而使网格图的状态复杂度降低。最后给出方法证明、算法思想、具体的算法描述和实验结论等。

关键词: 线性分组码, 最小网格, 网格复杂度, 校验矩阵置换