Research purposes: The basic component of the track structure with isolated rubber floating slab is the concrete slab track born by the elastic element.The research was done on the mechanical properties of the floating slab,the analysis was made for the natural frequencies,mechanical response under dynamic load and damping performance,and the discussion was made on the reasonable thickness of the ballastless track to provide the reference to the track design. Research conclusions:The research results show that the natural frequency of the track system decreases with the increase of the thickness of the ballastless track,and the rate of change decreases with increase of the track thickness.The acceleration insertion loss of the track basis increases with the increase of the thickness of the ballastless track,and the rate of change decreases with increase of the track thickness.When the thickness of the ballastless track reaches at 0.4m,the corresponding dynamic performance,the damping performance effect and the concrete amount of track bed are rather economical.From the present theoretical analysis and online testing,it can be seen the damping performance effect of the isolated rubber floating slab system is obvious,and its construction and maintenance programs are systematic.