Abstract: The design parameters of gusset plate and collapsing plate in a blown film line were determined through theoretical calculation in this paper. The upper and lower adjusting mechanisms, and four-bar mechanism used in the gusset plate were introduced. Various measures were taken to eliminate the wrinkles on film: calibration of each part assembly, increasing film bubble cooling effect, adjusting several angles, including the gusset plate angle, inserting angle, and top angel .