With the development of distributed power generation and microgrid technology, there are more and more application scenarios of inverters with different control methods in hybrid parallel connection. The hybrid parallel system based on virtual synchronous generator control and PQ control inverter has a wide range of applications. It is of great significance to explore the influence of the mutual coupling between these two control methods on the system stability. This paper mainly establishes impedance model and studies the influence of the phase-locked loop of the PQ-controlled inverter, the drooping link and the inertial link of the VSG-controlled inverter on the stability of the system. The influence of control parameters on system stability is analyzed by Generalized Nyquist criterion and verified by simulation and experiment.