Motivated on the idea of USSORP method and PCG method, a two-step method for solving an unsymmetrical linear complementarity problem with tridiagonal matrix is proposed.

• 基于非对称逐次超松弛迭代法和投影共轭梯度迭代法的思想，文中提出了一类求解系数矩阵为三对角非对称M矩阵的线性互补问题的USSORP-PCG算法-两步迭代法。