The Cook-Toom algorithm is widely used in short-length linear convolution, which is the building block of large points convolution algorithms. This paper proposes improved parallel finite impulse response (FIR) filter structures for linear-phase FIR filter, which is based on the Cook-Toom algorithm. In the proposed structures, Cook-Toom algorithm is used to reduce the number of sub-filters, and the symmetric properties of the linear-phase FIR filter’s coefficients is used to further reduce the number of multipliers in sub-filters. Compared with the reported FFA and ISCA parallel FIR filter structures, the proposed method can substantially reduce the computational complexity. Specifically, for a 8-parallel 144-tap filter, the proposed design saves 18 multipliers (5%), 45 adders (7.9%) compared with the structure based on Winograd convolution algorithm [7].