The utility model provides a glass fiber muscle of diameter difference and connection structure of reinforcing bar, includes the glass fiber muscle that links together through the U -shaped buckle and the link of reinforcing bar, the link of glass fiber muscle and reinforcing bar overlaps to fasten in the U -shaped buckle each other is in the same place, and its characterized in that, glass fiber muscle diameter be greater than the bar diameter, clearance between two inboards that the U -shaped card is relative of the both sides of reinforcing bar and U -shaped buckle sets up the backing plate, should fill up the plate thickness and equal with this clearance. The utility model discloses an useful result is: use the method of the fixed reinforcing bar of backing plate and can effectively solve glass fiber muscle diameter and the not synchronal problem of being connected of bar diameter, compare in using glass fiber muscle and the steel bar connection with the equal diameter, can greatly reduce the use quantity to the reinforcing bar for the shield method construction is practiced thrift more, the environmental protection, so as to accelerates the construction speed that the shield constructs, has greatly improved the shield moreover and has constructed the security of starting and receiving.