A network attack detection device is provided, including a spatial coordinate database for storing spatial coordinate data; a standard time zone database for storing standard time zone data; a domain name system packet collector for collecting a domain name system packet; a spatial snapshot feature extractor for extracting internet protocol address corresponding to the domain name system packet according to the domain name system packet, and generating spatial feature data corresponding to the internet protocol address according to the internet protocol address, the spatial coordinate data and the standard time zone data; and an attack detector for determining whether the domain name system packet is an attack according to the spatial feature data and a spatial snapshot detection model, and when determining that the domain name system packet is an attack, sending a warning to indicate the attack.