By using the time-dependent quantum wave packet method, we report a detailed dynamics study of H exchange reaction $H'(²S) + CH(X²\Pi) → H(²S) + CH'(X²\Pi)$ and the isotope effects of $H(²S) + CH(X²\Pi) → C(¹D) + H_2(X¹Σ^+_g)$ reaction on the 11A BHL potential energy surface. The reaction probabilities and integral cross sections have been obtained for the initial states $v = 0$ and $j = 1$ of the reactant molecules. The dense resonance structures in the reaction probabilities at all total angular momentums indicate complex-forming mechanisms for both $C + H_2$ and $H + CH$ products. A comparison between the results from centrifugal sudden approximation and those from close-coupled calculations demonstrates that the Coriolis coupling effects get more and more pronounced with increasing of $J$ for both $H$ exchange reaction and $CH$ decay reaction. The isotopic $D$ substitution of reactant significantly influences the $CH$ decay reaction. Moreover, it is revealed that the dynamical features such as partial wave contributions to the cross section are substantially different for these two channels.