The application discloses an air cylinder assist device for pulse jet dust collection experiments, which comprises a mounting plate, an expansion rack, a support plate, two mounting rails, and at least four bearing plates. Two ends of the expansion rack are fixedly fitted to the support plate and the mounting plate respectively; the mounting plate is provided with two slideways parallel to each other; sliders are arranged on the mounting rails and are slidably and tightly fitted to the slideways; one ends of the mounting rails are attached to the mounting plate; the mounting rails and the slideways are in perpendicular pound-mark-shaped distribution; all the mounting rails are provided with the bearing plates; each bearing plate has an arc bearing face, and one end of the bearing face is attached to the mounting plate; both the mounting rails and the sliders are provided with through holes; the mounting rails are movably fixed to the mounting plate via springs and bolt components, andscrews of the bolt components penetrate the through holes of the mounting rails and sliders.