An anaerobic reactor and an anaerobic wastewater treatment process are described herein. The anaerobic reactor includes a tank body (1) and a sludge scraper (4). The tank body (1) has a reaction chamber (11) therein. The reaction chamber (11) has a wastewater inlet (2) and a biogas outlet (3). A sludge collecting groove (6) is defined on the bottom surface of the reaction chamber (11). A sludge outlet pipe (12) in communication with the sludge collecting groove (6) is defined in an inner wall of the tank body (1). The sludge scraper (4) includes a sludge scraping plate (41) and a driving device (5). The sludge scraping plate (41) is located on the bottom of the reaction chamber (11), and is configured to scrape sludge on the bottom surface of the reaction chamber (11) into the sludge collecting groove (6). The driving device (5) is arranged on the bottom of the tank body (1) and connected to the sludge scraping plate (41) to drive it to rotate.
