Oil-paper capacitance plates is the important part to the main insulation of oil-immersed current transformer,its broken defect will influence the safety and reliability of power equipment directly.Based on the essential configuration feature of real oil-immersed inverted current transformer,experimental platform was set up and insulation defect was made in this paper firstly,and then the partial discharge characteristics of capacitive screen broken Defect for oil-immersed inverted current transformer were studied with pulse current measurement based on end-screen method.the results showed that for this kind of defect,the partial discharge shows out the feature of surface discharge,the magnitude of primary discharge pulse is low,the pulse time is only hundreds of ns.On the other hand,the discharge mainly concentrate at the trailing edge of positive power frequency phase and rising edge of negative power frequency phase.The frequency of discharge pulse mainly appear at 20MHz and 1MHz.Besides,under different testing voltage,the partial discharge characteristics are coincident and show good stability,which means that it can be used for diagnosis of insulation defect of inverted CT.