The development of intelligent transportation is of great significance to improving the effectiveness and safety of traffic. A new two-lane lattice hydrodynamics model (LHM) is proposed by simultaneously considering the effects of lane-changing and mixed traffic of connected and non-connected vehicles (CNVs). Using linear analysis, the stability conditions are derived, which indicates that lane-changing has a positive impact on traffic stability. In addition, the numerical simulation results provide support for theoretical analysis and confirm the correctness.