Ultra-high pressure container for producing gallium nitride crystal

The invention relates to an ultra-high pressure container for producing a gallium nitride crystal. The ultra-high pressure container comprises a cylinder body, an upper structure and a lower structure; the outer part of the cylinder body is provided with a heating strip and a heat insulation layer; the lower structure includes a lower sealing plug placed at the inner part of the upper end of the cylinder body and a lower thread pressing ring; the upper structure comprises an upper sealing plug placed at the inner part of the upper end of the cylinder body and an upper thread pressing ring; the upper sealing plug is connected with the radiating pipe through threads, and the upper part of the radiating pipe is connected with an ammonifying device; the lower sealing plug, the lower thread pressing ring, the cylinder body, the upper sealing plug, the upper thread pressing ring and the radiating pipe are made of high-temperature alloy material; the inside diameter of the cylinder body is 30 mm-250 mm, the working