The invention relates to a method for environmentally friendly preparation of vitamin B6 and recycling of tail gas. The method comprises the following steps: carrying out a catalytic formylating reaction on carbon monoxide, hydrogen and 2-cyano-2-cis-butene-1,4-diol which is used as a starting material to prepare a 2-hydroxymethyl-3-cyano-4-hydroxy-n-butyraldehyde intermediate, condensing the intermediate with 2-aminopropionate or 2-aminopropionate hydrochloride, and carrying out salt formation to prepare the vitamin B6. The method does not use a 4-methyl-5-alkoxyoxazole intermediate that is expensive and generates a large amount of wastewater in the production process, and allows the tail gas to be recycled in synthesis of the starting raw material, so the method has the advantages of environmentally friendly process, high reaction selectivity, high product purity, high atom economy, and suitableness for the green industrial production of the vitamin B6.