The invention discloses a thermomyces lanuginosus lipase gene, engineering bacteria and an application of the engineering bacteria. The base sequence of the thermomyces lanuginosus lipase gene is shown in SEQ ID NO.2. On the basis that existing thermomyces lanuginosus lipase amino acid sequences and protein structures are not changed, factors adverse to protein expression, for example, rare codons, rare codon pairs, strong stem-loop structures, potential early termination signals and the like are avoided, and the thermomyces lanuginosus lipase gene sequence is optimized, so that the sequence can efficiently express thermomyces lanuginosus lipase in a pichia pastoris recombination expression system, and the expression vitality is up to 370.65 U/ml and is improved by 58.38% while compared with the recombination expression vitality of the original sequence of the thermomyces lanuginosus lipase gene being 234.03 U/ml.