The work aims to look for corrosion inhibitors that effectively inhibit magnesium alloy corrosion and improve the quality of coating. Effects of corrosion inhibitors in different types and amounts on inhibiting corrosion of magnesium alloy and effects of different corrosion inhibitors on electroless nickel plating were studied. The performance of the corrosion inhibitor was evaluated by total immersion and weight loss test and the properties of nickel coatings with different corrosion inhibitors were characterized by scanning electron microscopy (SEM), energy disperse spectroscopy (EDS), X-ray diffractometer (XRD) and electrochemical tests. After a preliminary screening, the effects of hexamethylenetetramine, NH4F and NH4HF2 are more obvious. The corrosion rate of AZ9lD magnesium alloy firstly decreased and then increased with the addition of hexamethylenetetramine concentration in the corrosion solution. With the addition of NH4F and NH4HF2, the corrosion rate decreased gradually. The electrochemical curve measured in the system after addition of corrosion inhibitor was lower than that of the system without corrosion inhibitor. The effects of hexamethylenetetramine, NH4F and NH4HF2 reached the best at mass fraction at 1%, 1.5%, 2% respectively. All inhibitors regardless of type could effectively inhibit the corrosion of magnesium alloys and reduce the corrosion current. The deposition and plating effect of electroless nickel plating added with corrosion inhibitors was obvious and the electrochemical performance also improved greatly. Hexamethylenetetramine, NH4F, NH4HF2 corrosion inhibitor can effectively inhibit the corrosion of magnesium alloys and improve the quality of electroless nickel plating.