Nanolaser (NL), as an important optical source device, has a significant influence on photonic integrated circuits and has become a research hotspot in recent years. In this work, the synchronization performance of a dual-channel laser chaotic multiplexing system is investigated based on NLs and an active-passive decomposition is used to enhance signal processing and multiplexing efficiency. By establishing a rate equation model, the synchronization characteristics of the system are analyzed, with a focus on two key parameters— Purcell factor (F ) and spontaneous emission coupling factor (β )—as well as the effects of system parameters, single-parameter mismatch, and multi-parameter mismatch. Numerical simulations show that with appropriate parameter configurations, the two master NLs can maintain low correlation, ensuring the "pseudo-orthogonality" of chaotic signals while achieving high-quality chaotic synchronization with their paired slave NLs. In this work it is found that both the Purcell factor (F ) and the spontaneous emission coupling factor (β ) significantly affect the synchronization performance of the system, and the optimal parameter ranges for achieving high-quality synchronization are identified. Additionally, the effects of feedback strength and frequency detuning are explored, revealing that frequency detuning plays a more critical role in the synchronization between the master NLs. The influence of parameter mismatches on system synchronization performance is also emphasized. The system exhibits robustness against single-parameter mismatch and has minimum influence on master-slave synchronization quality. However, multi-parameter mismatch gives rise to more complex effects. Compared with the traditional semiconductor laser systems, this system can maintain “pseudo-orthogonality” over a wider range of parameters, thus achieving higher security and lower channel interference. This research lays a theoretical foundation for chaos synchronization based on NLs and provides new insights for designing secure, stable, and efficient optical communication systems.