The invention discloses a nonlinear measuring 
system capable of changing 
light intensity. The nonlinear measuring 
system comprises a programmable 
laser, a stepping displacement platform and a controlbox, wherein a mirror 
machine is arranged above the programmable 
laser; a first aperture diaphragm is arranged on one side of the mirror 
machine; the stepping displacement platform is placed on one side of a first convex lens; a BS (
Beam Splitter) 
prism is arranged on one side of the stepping displacement platform; a first 
detector is placed above the mirror 
machine; and one end of the first 
detector is connected with the control box by a wire. The nonlinear measuring 
system provided by the invention solves problems of influence on precision of nonlinear refractive coefficient, lack of measurement under 
Gaussian beams with different light intensities, lack of intelligence and 
automation, and lack of research on changes of a 
nonlinear absorption rate and a 
nonlinear refractive index of a substance under different light intensities by arranging structures such as the mirror machine, the first 
detector, the programmable 
laser, the control box, the first aperture diaphragm, a second aperture diaphragm, the BS 
prism and the stepping displacement platform.