The invention discloses a multi-channel on-chip integrated ultra-fast all-optical light intensity controller and a control method thereof. The invention designs a series of sub-wavelength branch waveguides as output channels, and couples them to different positions of a main waveguide by side coupling; the two oppositely propagating waveguide modes excited in the main waveguide are coherently superimposed to generate a standing wave light field; the output light intensity of these output channels are controlled according to the initial phase difference between the oppositely propagating waveguide modes in the main waveguide, so that a nano-scale multi-channel all-optical light intensity controller is realized on the basis of the linear optical method, which can work in any low light intensity in principle; the all-optical light intensity controller has a femtosecond ultra-fast response function; and the nano-scale multi-channel all-optical light intensity controller and the all-opticalcontrol method thereof are widely used in the field of nanophotonics.