The invention provides a purification process of G-type
natriuretic peptide. The purification process comprises the following steps: S5, treating a GNP
cracking intermediate crude product; s6, first-step purification: taking 0.2% TFA.H2O as a mobile phase A and
acetonitrile as a mobile phase B, preliminarily separating the oxidized crude product solution obtained in the step S5, collecting to obtain a component 1, a component 2 and a component 3, and continuously and circularly purifying the component 1 and the component 3 until the component 2 is obtained; s7, second-step purification: a mobile phase A is 50mmol / L Na2SO4, the pH is 2.3, a mobile phase B is
acetonitrile, the mobile phase A is used for purifying and separating the component 2 collected in the step S6 into components 4-6, and the component 4 and the component 6 continue to be circularly purified into a component 5; s8, third-step purification: a mobile phase A is 50mmol / L Na2SO4, the pH is 2.3, a mobile phase B is
acetonitrile, the mobile phase A is used for purifying and separating the component 5 collected in the step S7 into components 7-9, the component 7 and the component 9 are continuously and circularly purified into a component 10, and the component 10 is recycled to the component 8; s9, purification in the fourth step: a mobile phase A is 0.2% HAC.H2O, and a mobile phase B is acetonitrile. The problems that GNP obtained through
chemical synthesis is low in purity and poor in yield are solved.