A gasification apparatus for solid fuel, especially an apparatus for producing syngas by pressurized gasification of coal powder, including a gasification chamber (II) and a syngas cooling and purification chamber (III). The inner wall of the gasification chamber is a water-cooling wall (4). The inner side of the water-cooled wall is evenly coated with a layer of fire-resistant material (16). There is an annular cavity between the water-cooling wall of the gasification chamber and the furnace body. A syngas quencher, a vertical pipe (22), a gas distribution device (24), a defoaming device, and a dewatering and deashing device (21) are provided in the syngas cooling and purification chamber. The apparatus has a simple structure and is easy to operate. A high temperature gasification method for dry powder of carbonaceous material comprises spraying the combustible material and oxygen into the furnace and followed by ignition.