Monoglycosides acid purification method

The invention discloses a purifying method of monoglycoside acid, which comprises the following steps: oxidizing primary hydroxy group of the monoglycoside; exchanging the reacted composite liquid through activated strong acid cation exchange resin bed; eluting the ion exchange bed through purified water as elution. The invention separates the monoglycoside from inorganic salt effectively, which can be applied to manufacture monoaldonic acid lactone directly with simple technique and low cost.