A photonic chip and a preparation method thereof are provided. The chip includes a lithium niobate film modulator array, a first optical coupling array, and a silica waveguide wavelength-division multiplexer, and the lithium niobate film modulator array includes one or more lithium niobate film modulators and is used to modulate an optical signal; the first optical coupling array includes one or more first optical coupling structures, and the first optical coupling structure has one end connected to a corresponding lithium niobate thin film modulator and the other end connected to the silica waveguide wavelength-division multiplexer so as to transmit the modulated optical signal to the silica waveguide wavelength-division multiplexer; and the silica waveguide wavelength-division multiplexer is used to perform wavelength-division multiplexing on the modulated optical signal.