Abstract: A link balance adjustment method includes the following steps. A connection port initiates a balance adjustment process through an interrupt signal. A microprocessor provides an adjustment parameter for an external device from a register and transmits the adjustment parameter to the connection port. A measurement signal is initiated by the microprocessor, and the measurement signal enables the connection port to measure the signal quality after the adjustment parameter has been applied by the external device. The microprocessor determines whether the connection port needs to perform a preprocessing. When the microprocessor determines that the connection port needs to perform a preprocessing, the connection port performs the preprocessing and generates preprocessing data. The connection port transmits the preprocessing data to the register. The microprocessor reads the preprocessing data or the signal quality in the register.