In order to solve the problem that the thickness of aluminum coating of aerospace fasteners caused by manual spraying exceeds the standard requirement limit,and the uniformity,stability and controllability are poor,a research on fully automatic warm roller spraying process for small-sized(rod diameter 4~6 mm)bolt products is carried out.By verifying and optimizing the eight spraying parameters,including spray distance,spray amplitude,spray frequency,temperature,zirconium bead ratio,rotational speed,paint output and pressure,the optimal combination of spraying parameters is obtained to make the product appearance,thickness and adhension meet the standard requirements,which significantly improves the thickness uniformity of aluminum coating.