The invention discloses a novel production process for a sand box applied to casting of fan castings. The novel production process comprises the following steps: step (S1) blanking; step (S2) scribing; step (S3) splicing; step (S4) performing spot welding; step (S5) performing full-length welding; step (S6) deslagging; and step (S7) performing simple thermal treatment. The production process for casting of the fan castings, disclosed by the invention, can effectively guarantee the dimensional precision of the sand box; a temporary scaffold which consists of large square tubes and small squaretubes can provide protection for a welding worker and eliminate potential safety hazards; besides, the simple thermal treatment provided by the production process can eliminate residual internal stress after a wallboard is welded so that the wallboard is flat and straight; the production process is suitable for prying a wallboard of which the angle is equal to or smaller than 3 degrees; and the production process effectively lowers the casting cost and is high in practicability.