Provided are an elastomeric-hose-compressing part, a cartridge, and a roller assembly for a pump head of a peristaltic pump, and a pump head for a peristaltic pump. The elastomeric-hose-compressing part includes a surface for compressing the elastomeric hose which has an arcuate shape along its length direction, wherein the surface for compressing the elastomeric hose is provided with flanges oppositely arranged on two side portions of the elastomeric-hose-compressing part in the width direction, the width direction of the elastomeric-hose-compressing part is perpendicular to the length direction, and the surface for compressing the elastomeric hose is formed by a continuous surface or by a plurality of surfaces sequentially arranged along the length direction. By providing flanges at two sides of the surface for compressing the elastomeric hose, the elastomeric-hose-compressing part as disclosed may reliably limit the elastomeric hose between the surface for compressing the elastomeric hose and the roller assembly of the peristaltic pump, which thus reduces abnormal abrasion of the elastomeric hose.