<p>To address the challenge of accommodating high screening throughput in confined environments, the vibration synchronization of a parallel vibration system is investigated in this paper. Meanwhile, the slanted elliptical motion is proposed to optimize screening and transport capacities while reducing the risk of screen mesh clogging. This system allows simultaneous operation of the upper rigid body (URB) and lower rigid body (LRB) with different screening motions. Firstly, by introducing a mechanical space model with perturbations related to the phase difference (PD) and vibrator velocity, the synchronization theory, numerical calculations and simulations are conducted. Then, to verify reliability, systematic experiments are introduced based on constructed testing scheme, by employing a detection method for the stable and unstable PDs from tested amplitude. Results indicate that the influence of the URB and LRB is smaller than that of the vibrators in far resonance conditions, and chaotic regions I and II, as well as skewing angle between two eccentric rotors within vibrators, should be avoided. The in-phase synchronization state can be enhanced by increasing installation parameters <i>β</i>_<i>zτ</i> and <i>l</i>_<i>y</i>. This study offers theoretical basis for designing and monitoring the drilling vibration screen and mining screening machinery.</p>