The layout of 1×N optical power splitters with uniform outputs and low excess loss is presented in this paper. The novel splitter consists of cascaded asymmetric Y-branch waveguides based on total internal reflection. Its optical characteristic is thoroughly simulated and analyzed by using finite-difference beam propagation method (FD-BPM). The simulated results show that the power uniformity of the splitters is less than 0.3 dB at wavelength of 1.55 μm. The proposed structure has the advantages such as simple structure,low-loss,little dependence of wavelength and polarization.