Abstract: A new experimental scheme to measure the gravitational constant G between big objects is introduced.Firstly,the overall arrangement of the new experimental scheme is presented.Then,the anticipated observation value is analyzed.Finally,the error in the new experimental scheme is analyzed and the method to reduce the error is put forward.Analysis shows that the displacement of small objects' shadow on the screen will be 3.75 mm.

Key words: gravitational constant G, torsion balance, precision, displacement