Inwall finishing machine for small-diameter steel pipes, and grinding head thereof

The invention discloses machine tool equipment and particularly relates to an inwall finishing machine for small-diameter steel pipes, which is adaptive to error changes of the inwalls of small-diameter steel pipes. A grinding component with a grinding support block, a slant fitting structure and a spring is provided, thus transverse force generated by the spring is converted into force for ascent of the grinding support block and transverse force, and the grinding support block is urged to move up. When the inwall of the small-diameter steel pipe is machined, the grinding support block moves up and down naturally with diameter errors and ovality errors of the inwall of the steel pipe, and accordingly the grinding radius of an abrasive tape on the grinding support blocks changes with the inwall errors of the steel pipe, namely the spring can provide sufficient external grinding force for the abrasive tape through the grinding support block. Therefore, the inwall finishing machine for small-diameter steel pipes can be adaptive to machining small-diameter steel pipes.