Aiming at the problem that the number of layers of subwavelength grati ng power beam splitter that can achieve multi-splitting is difficult to prepare and cannot be split evenly,this paper designs a single layer subwavelength grat ing power beam splitter based on beam reflection convergence function,which can realize more beam splitting and is easy to preparation.Using the rigorous coup led wave analysis and the wavefront phase control principle,the four identical s ubwavelength grating with beam convergence function are designed.Then the chose d four same subwavelength gratings are closely splitted and then the four ways p ower splitter are obtained.By designing the model in the finite element softwar e COMSOL,the simulation results show that the device can divide a bundle of the TM incident light with a wavelength of 1550nm into four bun dles of beams,an d each beam have the same power and realize reflective convergence.Therefore,the power beam splitter based on the wavefront phase control principle can not only realize multi-beam average splitting,but also realize convergence of each bea m ,which can effectively improve the working efficiency of the photodetector arra y,and is expected to be widely used in optical communication integration system and space light coupling and other fields.