The invention provides an echo suppression method and an echo suppression device based on an Articulated Naturality Web (ANW), which relate to the technical field of the Articulated Naturality Web. According to the echo suppression method and the echo suppression device provided by the embodiment of the invention, received first audio data transmitted by a first ANW terminal is decoded and playedat first, then second multimedia data comprising second audio data is acquired, then the second audio data is subjected to echo suppression processing, such that a difference value between the data size of the second audio data and the data size of the first audio data is within a preset range, further the time difference between the second audio data and the first audio data is ensured to be within a reasonable range. Therefore, after the processed audio data is transmitted to the first ANW terminal, when the first ANW terminal plays the second audio data, a user cannot perceive echo in the second audio data, thereby further avoiding echo interference, and improving call quality.