The invention provides a wide-range scanning broadband laser phased array system, which comprises a plurality of laser phased array subsystems which are sequentially arranged along y-axis direction, wherein the subsystem is composed of a cladding layer (3) and an incident optical fiber (1), a coupling grating (2), a cladding layer (3), a power distribution network (4), an electro-optical attenuator (5), an electro-optical phase shifter (6), a plasma excitation element antenna array (7) and an optical waveguide (8) which are integrated on the cladding layer (3); the incident laser of the incident optical fiber is coupled into the optical waveguide by the coupling grating, and the laser energy in the waveguide is evenly distributed to multi channels of optical waveguides through the power distribution network, the intensity of the laser in each waveguide is controlled by the electro-optical attenuator and the phase is controlled by the electro-optical phase shifter to generate a phase difference between adjacent waveguides and the laser is radiated into free space from the plasma excitation antenna array. The scanning angle range and the working bandwidth of a prior laser phased array can be effectively improved.