A turning peg structure equipped with changeable faceplate to drive a winding shaft assembly of a string instrument to adjust the tightness of a string. The turning peg structure includes a bracket, at least one first faceplate, at least one second faceplate and a linking rod. The bracket includes a plate and a passage embedded in and run through the plate. The plate includes a first side and a second side opposite to the first side. The first faceplate includes a first connecting portion connected to the first side of the bracket. The second faceplate includes a second connecting portion connected to the second side of the bracket. The linking rod has one end located in the passage and another end engaged with the winding shaft assembly. Through the bracket, the turning peg structure does not lose string adjustment function due to damage thereof.