The design and simulation of a new and high efficiency heterostructure beam splitter are proposed based on the coupling characteristics between the waveguide and ring resonator in two dimensional photonic crystals. The splitting properties of the beam splitter are numerically studied using the finite difference time domain method. By simply tuning dielectric constant of dielectric rods and inducing the redistribution of the power of the optical field, uniform or free splitting can be achieved. It is shown that a small dimension, a large separating angle and a high beam rate are extended to have more light output channels in the beam splitter at optical communication wavelength. These features of the proposed heterostructure ultracompact multiway beam splitter make it a promising candidate in optical communications application.