The dynamic Stark effect on the dynamical behaviors of atom and squeezed state field in-two-photon processes is studied by a model consisting of an effective two-level atom with multiple levels and quantized field with single mode. The dynamic Stark effect will cause the decreasing of the revival amplitude and the shortening of the period of the atomic Rabi osoillation of inversion, and the increasing the speed of energy exchange of an atom with the field. This is favorable to the enhancement of the photon antibunching and the narrowing of the Poisson distribution of photons. However, it will make the squeezing of field to decrease, even disappear.