A noise-reduction method for processing a port is applied to a test target for testing or being burned in with software. At least one zero-Ohm resistor is provided with a first end thereof electrically connected to a device under test (DUT) of the test target and a second end thereof connected to a test port. Moreover, at least one grounding zero-Ohm resistor is provided with one end connected to ground and the other end is a floating end. After the test target is finished debugging or burned in with software, the connection of the first end and the DUT is disabled, and the second end is connected to ground through the floating end to reduce noise generation and improve a flexibility in circuit layout.