To investigate how DNA methylation affects the interaction between DNA sequences and proteins， as well as its influence on cellular functions. This study compared methyltransferase mutant Lacticaseibacillus paracasei Zhang Δ2054 with wild-type Lacticaseibacillus paracasei Zhang by ultra-high performance liquid chromatography and mass spectrometry also conducted multivariate statistical analysis of the differential metabolites in the logarithmic growth period (12 h)， combined with database search and mass spectral information matching， and obtained a total of 33 significantly different metabolites， of which 10 and 23 significantly different metabolites were up-regulated and down-regulated respectively， mainly including purine， pyrimidine and their analogues， nucleosides， nucleotides and analogues， amino acids and their derivatives， carbohydrates and carbohydrate conjugates， etc. It is also concentrated in purine metabolism， pyrimidine metabolism， lysine biosynthesis， riboflavin metabolism， propionic acid metabolism， phosphate pentose and other metabolic pathways. Although the LCAZH_2054 gene is not the control gene of methylation phenotype， it plays an important role in the metabolism of strains. In this study， through metabolomics analysis， to reveal the growth and metabolism differences between methyltransferase mutant Lacticaseibacillus paracasei Zhang Δ2054 and wild type Lacticaseibacillus paracasei Zhang on chemically restricted medium. The effects of LCAZH_2054 gene on the utilization of nutrients and the production of metabolites during growth and metabolism were further discussed.