This invention discloses a signal receiving device for Ethernet and a control method thereof. The signal receiving device includes a gain control circuit, an alien near-end crosstalk canceller, a noise canceller, and a DFE. The gain control circuit adjusts an input signal of the signal receiving device according to a setting parameter. The alien near-end crosstalk canceller cancels an alien near-end crosstalk interference. The noise canceller uses a first filter to cancel noises. The DFE uses a second filter to cancel an inter-symbol interference of the input signal. The method includes steps of: temporarily stopping the gain control circuit from updating the setting parameter before a seed collision occurs, and temporarily stopping one of the noise canceller and the decision feedback canceller from updating the first filter coefficient of the first filter or the second filter coefficient of the second filter temporarily during the seed collision.