The invention discloses a mixed gas transformation method for a 110 kV sulfur hexafluoride gas insulation current transformer. The mixed gas transformation method comprises the following steps that firstly, an original SF6 gas insulation current transformer body is utilized, gas chamber china bottle bearing pressure and explosion-proof film bearing pressure of the original SF6 gas insulation current transformer body, and the matching relation between the gas chamber china bottle bearing pressure and the explosion-proof film bearing pressure, and mixed gas charging pressure are rechecked; secondly, SF6 gas in the SF6 gas insulation current transformer is recycled; and thirdly, SF6/N2 mixed gas with the specific ratio and pressure are injected in the SF6 gas insulation current transformer through a mixed gas charging device. The existing SF6 gas insulation current transformer is transformed, not only is the site insulation requirement met, but also the purposes of reduction and replacement of the SF6 gas are achieved, and the mixed gas transformation method is easy to implement and low in cost.