The invention discloses a combustion device for a W-flame boiler and the W-flame boiler. A plurality of primary gas nozzles (1) connected with a hearth are arranged at the tail end of a primary gas pipeline (9); one or more exhaust gas nozzles (2) connected with a vertical wall (4) of the boiler are arranged at the tail end of an exhaust gas pipeline (10); a plurality of secondary air nozzles connected with the hearth are arranged at the tail end of a secondary air pipeline; the multiple primary gas nozzles (1) are gathered, and the secondary air nozzles are arranged around the multiple primary gas nozzles. According to the combustion device and the W-flame boiler, the primary gas nozzles are gathered, so that the ignition of pulverized coal particles is strengthened; the exhaust gas nozzles are arranged at a fixed position of the vertical wall, so that the ignition of exhaust gas flow is facilitated; the secondary air nozzles are arranged around the primary gas nozzles, and each nozzle and a water-cooled wall surface are arranged to form a certain angle, so that the combustion is strengthened, and NOx generation is controlled. The primary gas nozzles are wrapped by the secondary air nozzles, so that the effect that pulverized coal is coated by air is achieved, the water-cooled wall of the hearth is protected, and slag formation is effectively prevented.