Based on the characteristics of the separable exponential matrix and the 2N-type algorithm, a fast precise integration method for the separable exponential matrix was proposed. The key idea is that the blockmatrix is computed based on the submatrix of the separable matrix,thus increasing the reserved item numbers in the Taylor series expansion and decreasing iterative times. On the one hand, the programming is easy. On the other hand, the numerical examples show that the method presented for the large dimension separable exponential matrix can reduce the computation and storage amount and greatly improve the calculation efficiency.