The invention discloses a non-destructive replacement device for an electric energy meter and a replacement method thereof, belongs to the technical field of power equipment, and solves the problem that the electric quantity cannot be calculated when an existing multifunctional electric energy meter is replaced, which causes the loss of a power supply enterprise. According to the replacement method of the invention, a secondary current of an operation electric energy meter loop is shunt; a first electric energy meter installation plug-in and a second electric energy meter installation plug-inare installed in parallel in a secondary current loop; the two electric energy meter installation plug-ins are respectively used for installing an electric energy meter to be replaced and a replaced electric energy meter; in the process of replacing the electric energy meters, the electric energy meter to be replaced and the replaced electric energy meter are installed alternatively through the two electric energy meter installation plug-ins; a secondary current operation loop of one of the electric energy meters is disconnected, a secondary operation loop of the other electric energy meter isconnected with the operation electric energy meter loop, uninterrupted metering is achieved, and therefore non-destructive replacement is achieved. The replacement method provided by the invention isused for replacing the multifunctional electric energy meter.