The disclosure provides a device and a method for determining electrocardiography (ECG) signal. The method includes: obtaining a first electrical signal and generating a second electrical signal based on the first electrical signal； normalizing the second electrical signal as a third electrical signal； and obtaining a noise characteristic of the third electrical signal； and determining whether the third electrical signal is an analyzable ECG signal based on the noise characteristic of the third electrical signal.本發明提供一種心電圖訊號判斷裝置及其方法。所述方法包括：取得一第一電訊號，並基於第一電訊號產生一第二電訊號；將第二電訊號正規化為一第三電訊號；取得第三電訊號的一雜訊特性；以及基於第三電訊號的雜訊特性而判斷第三電訊號是否為一可分析的心電圖訊號。
