A rubber strip manufacturing method that includes a step of extruding a rubber from an extrusion orifice of an extruder includes: a step of forming a long rubber member by extruding the rubber from the extrusion orifice that is circular; and a step of forming a rubber strip by passing the long rubber member through a gap between a pair of rotating rollers. The gap has a shape that is the widest in a central portion in a direction parallel to rotation axes of the rollers and that narrows as a distance from the central portion increases.