This paper analyzed the dynamic characteristics and the random seismic response of a super large hyperbolic cooling tower using 3-D FEM method. The results showed that the tower was very flexible. And it’s meridian direction axial force RMS was relatively bigger in the range of 40m-120m high, the maximum value of annular axial force RMS was at the top of the shell. Furthermore, using the principle of first passage failure mechanism, the dynamic reliability under 7 seismic intensity and different site conditions were analyzed and calculated, in which the structural drift at the height of 40m was considered as the failure criterion, and the dynamic reliability of the tower during the design reference period was obtained. Otherwise, the results of dynamic reliability under a seismic load based on Poisson hypothesis and Morkov hypothesis were also discussed.