According to current code for design of concrete structures,the formula of crack width checking on eccentrically tensioned prestressed members was deduced.Meanwhile,another form of the formula of crack width checking was also deduced based on two-stage-working principle.Similar to the union of ultimate bending strength calculation formulas of prestressed members,the union of crack width checking formulas derived from the two methods was also realized.What's more,the latter one simplified the process of crack width checking,making it easier for the crack control of prestressed concrete members.