This　paper　analytically　and　numerically　presents　global　dynamics　of　the　generalized　Boussinesq　equation　(GBE)　with　cubic　nonlinearity　and　harmonic　excitation.　The　effect　of　the　damping　coefficient　on　the　dynamical　responses　of　the　generalized　Boussinesq　equation　is　clearly　revealed.　Using　the　reductive　perturbation　method,　an　equivalent　wave　equation　is　then　derived　from　the　complex　nonlinear　equation　of　the　GBE.　The　persistent　homoclinic　orbit　for　the　perturbed　equation　is　located　through　the　first　and　second　measurements,　and　the　breaking　of　the　homoclinic　structure　will　generate　chaos　in　a　Smale　horseshoe　sense　for　the　GBE.　Numerical　examples　are　used　to　test　the　validity　of　the　theoretical　prediction.　Both　theoretical　prediction　and　numerical　simulations　demonstrate　the　homoclinic　chaos　for　the　GBE.