Non-ribosomal peptide synthetases catalyze the biosynthesis of structurally and functionally diverse non-ribosomal peptide natural products, which have broad applications in pharmaceutical, agricultural, and industrial sectors. Engineered non-ribosomal peptide synthetases can be used to produce novel non-ribosomal peptides through combinatorial biosynthesis. This conforms to the concept of green chemistry, thus attracts increasing attention across the world. Herein, three different engineering strategies were summarized, and recent advances in this field were reviewed.