  In this paper, we make a systematical and in-depth study on the chaotic
dynamics of the string around the conformal black hole. Depending on the
characteristic parameter of the conformal black hole and the initial position
of the string, there are three kinds of dynamical behaviors: ordered, chaotic
and being captured, chaotic but not being captured. A particular interesting
observation is that there is a sharp transition in chaotic dynamics when the
black hole horizon disappears, which is indepent of the initial position of the
string. It provides a possible way to probe the horizon structure of the
massive body. We also examine the generalized MSS (Maldacena, Shenker and
Stanford) inequality, which is proposed in holographic dual field theory, and
find that the generalized MSS inequality holds even in the asymptotically flat
black hole background. Especially, as the initial position of the string
approaches the black hole horizon, the Lyapunov exponent also approaches the
upper bound of the generalized MSS inequality.
