Candida antarctica lipase B (CALB) is one of the most widely used and studied enzymes in the world. In order to achieve the high-level expression of CALB in Pichia, we optimized the codons of CALB gene and alpha-factor by using a de novo design and synthesis strategy. Through comparative analysis of a series of recombinants with different expression components, we found that the methanol-inducible expression recombinant carrying the codon-optimized alpha-factor and mature CALB gene (pPIC9K alpha M-CalBM) has the highest lipase production capacity. After fermentation parameters optimization, th...