Provided herein are engineered decarboxylase polypeptides that are useful for catalyzing the decarboxylation of amino acids such as L-tyrosine to produce tyramine or catalyzing the decarboxylation of L-DOPA to produce dopamine. Also provided are the preparation process of engineered decarboxylase polypeptides as well as reaction process under industrial-relevant conditions. The disclosure also provides polynucleotide sequences encoding engineered decarboxylase polypeptides, recombinant host cells capable of expressing engineered decarboxylase polypeptides, and methods of producing tyramine or dopamine using the engineered decarboxylase polypeptides. Compared to the wild type decarboxylase, the engineered polypeptide provided by this disclosure has better activity and/or stability. The use of the engineered polypeptides for the preparation of tyramine or dopamine reduces the production cost and has a good industrial application prospect.