Research conclusions: The fastening on the track slab in small curve radius section would lose the much capability of adjusting height and distance． Therefore，it is proposed the I slab ballastless track should not be laid in the section with curve radius less than 1600 meters as much as possible． The bigger the curve radius is，the smaller the fastening vector is，the smaller the loss of the adjustment volume of the distance between rails is，the bigger the adjustment space between rails is in the maintenance stage and the smaller the decreasing difference of the superelevation of the track slab is． This benefits the construction and maintenance．