A DIY window curtain able to be combined by a user includes a plurality of hang rods and a pulley base. The hang rods are respectively inserted through the hang hole of a curtain, which is formed with pleated edges according to the length of each hang rod. The pulley base is provided with two symmetrical combining members to be symmetrically combined and fitted around the hang rod. The pulley base is fixed with a pulley rod having its pulley fitted in the rail groove of a sliding rail, enabling the window curtain to be assembled, shrunk or expanded.