Extracting the charging load pattern of residential electric vehicle (REV) will help grid operators make informed decisions in terms of scheduling and demand-side response management. Due to the multi-state and high-frequency characteristics of integrated residential appliances from the residential perspective, it is difficult to achieve accurate extraction of the charging load pattern. To deal with that, this paper presents a novel charging load extraction method based on residential smart meter data to noninvasively extract REV charging load pattern. The proposed algorithm harnesses the low-frequency characteristics of the charging load pattern and applies a two-stage decomposition technique to extract the characteristics of the charging load. The two-stage decomposition technique mainly includes: the trend component of the charging load being decomposed by seasonal and trend decomposition using loess (STL) method, and the low-frequency approximate component being decomposed by discrete wavelet technology (DWT). Furthermore, based on the extracted characteristics, event monitoring, and dynamic time warping (DTW) is applied to estimate the closest charging interval and amplitude. The key features of the proposed algorithm include (1) significant improvement in extraction accuracy; (2) strong noise immunity; (3) online implementation of extraction. Experiments based on ground truth data validate the superiority of the proposed method compared to the existing ones.