The interaction between a screw dislocation and a semi-infinite wedge-shaped crack in one-dimensional hexagonal quasicrystal is investigated by the conformal transformation method and the perturbation technique. Analytical solutions are obtained for the stress intensity factor of crack, and the force on dislocation. The effects of the dislocation location and the wedge angle on the image force of the dislocation are revealed. At the same time the influence of the dislocation on crack behaviour is also discussed in detail. The corresponding results of the sharp crack can be obtained as a special case of the present solutions (i.e. =1/2).