The invention discloses a rotary seal mechanism for clamping hollow tubular electrode wires in different diameters. The rotary seal mechanism for clamping hollow tubular electrode wires in different diameters comprises a rotary transmission mechanism, a seal mechanism and an electrode wire centering clamping mechanism. The rotary transmission mechanism comprises a rotary main shaft, a synchronous pulley and a C-type retaining ring. The seal mechanism comprises a guide block, a rubber seal plug, an O-type seal ring and a positioning connection post. The electrode wire centering clamping mechanism comprises a hinge press rod, a first guide pipe, a second guide pipe, a ceramic supporting block, a compression spring, the positioning connection post and an air cylinder. The rotary seal mechanism for clamping hollow tubular electrode wires in different diameters can be used for a rotary normally-closed clamp mechanism on a rotary main shaft of a blade air film cooling hole electric spark machine tool, can achieve high-precision clamping and rotating of tool electrodes, sealing of cavity high-pressure working fluid and centering clamping of electrode wires in different diameters, and is applied to the field of blade air film cooling hole machining, and some technical problems such as structural bottlenecks can be effectively solved.