The invention discloses a tee silicon-based beam splitter chip. The chip comprises an input waveguide, three output waveguides and a coupling area between the input waveguide and the output waveguides, wherein the coupling area is square, the input waveguide and the output waveguides are equal in width, the width K is greater than 490nm and is less than 510nm, the coupling area, the input waveguide and the output waveguides are equal in thickness, the thickness H is greater than 210nm and is less than 230nm, and the edge length L of the coupling area is greater than 1600nm and is less than 2000nm. The tee silicon-based beam splitter chip has high integration and small size, and makes wavefront reconstruction equipment more portable.