Production method of vitamin B6

The invention belongs to the technical field of vitamin production, and particularly discloses a production method of vitamin B6. The production method comprises the following steps: distilling and purifying an ester-acyl compound crude product obtained by ester acylation reaction to obtain an ester-acyl compound pure product and a distillation residue containing a byproduct 2, 2 '-oxadiamido ethyl dipropionate; then, hydrolyzing the distillation residues containing the by-product ethyl 2, 2 '-oxadiamido dipropionate; carrying out an ester acylation reaction on the obtained hydrolysate to prepare an ester-acyl compound, and purifying the reaction product to obtain a pure ester-acyl compound product; and using the obtained pure ester acyl for cyclization reaction. The invention provides the production method of vitamin B6, which is characterized in that a byproduct 2, 2 '-oxadiamido ethyl dipropionate is separated and utilized, so that the yield of an ester acylation reaction step is improved, and the problem