In this paper, the effect of electrons and positrons trapping on positive and negative ions are analysed in collision-less magnetised system. Relying on the widely used reductive perturbation technique (RPT), a three-dimensional (3D) modified trapped Korteweg-de Varies Burgers’ (mTKdVB) equation is governed due to the presence of trapped positrons, trapped electrons, and both kinematic as well as bulk viscosity. This study examines the influence of different parameters, such as negative ion number densities, electron ion densities, and positron ion density on dynamical and structural properties. Also, the impact of the viscosity coefficient and magnetised parameter of the small-amplitude shock waves has been examined. The current theoretical research may be helpful to understand the shock wave structure in space environments related to astrophysics such as white dwarfs, neutron stars etc.