Quantum key distribution (QKD) can distribute symmetric key bits between remote legitimate users with the guarantee of quantum mechanics principles. For practical applications, there is increasing attention to integrating the source, detectors, and modulators on a photonic chip. Here, the Kerr dissipative soliton is introduced in a microresonator as the light source for GHz QKD systems, and the proof-of-principle experiment demonstrates the parallel QKD can be achieved using coherent comb lines from the soliton. The performance of parallel QKD is also verified by using the off-the-shelf wavelength division modules and the on-chip soliton source. Since the on-chip soliton can provide hundreds of carriers covering the C and L bands, the results exhibit the feasibility to achieve ultra-high rate secure key bits through massively parallel QKD, especially when incorporated with the thriving photonic integrated circuit technology.