The invention belongs to the process for manufacturing a single crystal blade of an aircraft engine, and relates to a grain size corrosion device of the single crystal blade. The grain size corrosion device of the single crystal blade is characterized by comprising a corrosion groove (1), a first anti-corrosion pneumatic valve (2), a hydrochloric acid groove (3), a hydrogen peroxide groove (4), a second anti-corrosion pneumatic valve (5), a third anti-corrosion pneumatic valve (6), a fourth anti-corrosion pneumatic valve (7), a waste liquid basin (8), a fifth anti-corrosion pneumatic valve (9), a wastewater basin (10), a sixth anti-corrosion pneumatic valve (11), an alkaline basin (12), a pneumatic alkaline pump (13), an exhaust fan (14) and a console. The grain size corrosion device of the single crystal blade provided by the invention is used for removing environment pollution, protecting the physical health of an operator, reducing the labor intensity and improving the working efficiency.