The influence mechanism of normal stress and seepage pressure on seepage flow was analyzed by the seepage tests of artificial fracture under different normal loads by means of the experimental device of seepage flow in fracture radiation flow. All the normal loading gap scour marks were generally close to the surface. The washed area concentrated in the center of the specimen at the inlet, and the flow near the inlet had great turbulence. The seepage flow of different normal stress has a linear relationship with the infiltration head, which shows that the motion characteristics of the crack water in the experimental course accords with Darcy's law. The seepage flow rate was approximately the same under the same infiltration water pressure. The contact state between the upper and lower parts does not change with the increase of normal stress, but maintains a stable fracture opening. The water head loss increased rapidly from 0.1 MPa to 0.2 MPa with the infiltration water pressure, after 0.2 MPa the growth is slow and close to the straight line. The percentage curve of head loss increases first and then decreases. The fitting curve is three degree polynomial.