The invention provides an acrylic amidase strain-Trichosporon asahii 2-1 and application thereof in preparing an acrylic acid. The Trichosporon asahii 2-1 is collected in the China center for type culture collection of which the address is Mountain Luojia Wuhan University in Wuhan City, Hubei Province, 430072, with a collection date of January 19, 2010, and a collection number CCTCC No. is M2010017. The invention obtains a new strain producing amidase through screening and a mutagenesis strain with obviously enhanced amidase activity through mutagenesis improvement, prepares the acrylic acid by a biological method with the mutagenesis strain so as to replace a chemical synthesis method, and has the advantages of high conversion rate, environmental protection, green process, and the like. meanwhile, the acrylic amidase strain provides a most economic and effective method for treating aliphatic nitrile and amide compounds contained in industrial waste water because the strain can hydrolyze a highly virulent aliphatic nitrile compound and acrylic amide into acid substances with less virulence, thereby also having important practical significance in environmental improvement.