This paper analyzes hybrid operation characteristics of multi type current transformer for both sides of the line, deriving the differential current expression of hybrid operation by theory, and analyzing its influence factors. On this basis, it studies dynamic simulation testing method of hybrid operation of multi type current transformer, designs 6 kinds of testing schemes, makes the equivalent model based on the field of the P-level current transformer, the TPY-level current transformer and the electronic current transformer respectively, and builds the dynamic simulation testing platform of hybrid operation. Based on testing platform above, comparing the transmitting performance difference of multi type current transformer, through the action track and action state of hybrid operation in two successive out of the area fault, it analyzes the influence of hybrid operation on the differential protection and puts forward the corresponding improvement measures. This work is supported by Science and Technology Project of State Grid Corporation of China (No. DW1600017).