A differential phase shift beam splitter with a multi-layer dielectric film structure which is used for a division-of-amplitude photopolarimeter (DOAP) with an operating wavelength of 1064 nm is designed and prepared. The optimal parameters of beam splitter are obtained by analyzing instrument matrix parameters of the DOAP system. The beam splitter sample and its anti-reflection coating on the backside are prepared with the ion beam sputtering (IBS) deposition method. The experimental results are well consistent with the designed value. Comparing with single-layer film beam splitters, this multilayer dielectric film beam splitters possess a wider application, which is not limited by the substrate, layer materials, incident angle, and operating wavelength.