Multilayer film structure is designed for hohlraum used in inertial confinement fusion. It is similar to low density foam material but easier to be fabricated and more flexible to change its equivalent density. Simulations and experiment of laser ablated planar targets reveal that, compared with solid gold, plasma expansion of multilayer gold films is mitigated and the x-ray flux is increased. The laser spot moves inwards and its speed can be controlled by adjusting the gaps between films.