The present invention provides amino acid sequences of engineered decarboxylase polypeptides that are useful for catalyzing the decarboxylation of L-aspartate to produce β-alanine, and the preparation process of engineered decarboxylase polypeptides as well as reaction process under industrial-relevant conditions. The present disclosure also provides polynucleotide sequences encoding engineered decarboxylase polypeptides, engineered host cells capable of expressing engineered decarboxylase polypeptides, and methods of producing β-alanine using the engineered cells. Compared to the wild-type decarboxylase, the engineered decarboxylase polypeptide provided by the invention has better activity and stability, and overcomes the inhibition by L-aspartic acid and/or β-alanine. The use of the engineered polypeptides of the present invention for the preparation of β-alanine results in higher unit activity, lower cost, and has good industrial application prospects.