The optical beam splitter based on metal nanoslits containing nonlinear materials is designed and optimized. Finite-difference time-domain (FDTD) method is employed to numerically simulate optical beam splitting properties of TM-polarized plane wave with a wavelength of 850 nm via subwavelength silver nanoslits containing nonlinear materials InGaAsP. The results show that the number of output ports or energy distribution can be adjusted simply by changing the width, number or order of the nanoslits. The number of output ports can be dynamically controlled by changing the intensity of incident light. The symmetric structure of seven nanoslits possesses 1×5 symmetric optical beam splitting properties. Due to the more compact architecture, more output ports and the dynamical control method, the devices are important for potential applications in micro-nano photonic integration and optical communication.