Arc-shaped roof steel structure frame

The utility model relates to the field of civil engineering, in particular to an arc-shaped roof steel structure frame which comprises a roof body and I-shaped steel, the I-shaped steel comprises webs and flanges, a plurality of first purlines are longitudinally arranged above the I-shaped steel, and a plurality of second purlines are transversely arranged above the I-shaped steel. Two fixed plates I are arranged between the I-shaped steel and the purline I, the upper sides of the fixed plates I are connected with the purline I, and the lower ends are fixedly connected with the I-shaped steel; a fixing piece is arranged at the joint of the first purline and the second purline and comprises two vertical plates and a bottom plate, one sides of the two vertical plates are fixedly connected with the first purline, and the other sides of the two vertical plates clamp the end of the second purline. A third purline is longitudinally arranged above the second purline, two second fixing plates are arranged between the