The utility model provides a process pipeline assembling angle positioning device which comprises a horizontal ruler, two identical angulometers and a self weight pointer. The two angulometers are respectively hollow segmental ring-shaped bodies, center rods are arranged at the central axes of the two segmental ring-shaped bodies respectively, the two angulometers are arranged on the horizontal ruler after attached to each other, and the self weight pointer is installed on the center rods after the two angulometers are attached to each other, so that the self weight pointer is perpendicular to the horizontal plane by means of self gravity. The process pipeline assembling angle positioning device facilitates deviation rectification in the process pipeline assembling process and has the effects of efficiently assembling various pipelines.