The invention relates to the technical field of boiler equipment, in particular to a solid fuel gasification incineration boiler. The solid fuel gasification incineration boiler is simple in structure, few in arranged heated faces and capable of saving investment cost and operation cost, and the boiler is environmentally friendly and efficient. A feeding hopper is connected with a hearth, the hearth comprises a front arch, a first rear arch and a second rear arch which are sequentially and obliquely arranged, the first rear arch is lower than the front arch and the second rear arch, a core combustion area is formed by the front arch and the first rear arch, a smoke internal circulation loop is formed by the first rear arch and the second rear arch, and a clearance is reserved between the lower end of the first rear arch and the second rear arch. An air distribution bed is arranged at the position, below the inclined face of the lower portion of the first rear arch, of the bottom of the hearth, the lower end of the air distribution bed is connected with an air chamber, and a main combustion area is formed by the front arch at the upper end of the first rear arch and the second rear arch. A hearth outlet is connected with a cyclone separator, the particle outlet end of the cyclone separator is connected with one end of a loop flue, the smoke outlet end of the cyclone separator is connected with a tail flue, and the other end of the loop flue is connected with the smoke internal circulation loop.