<p>This paper examines the effects of a magnetic field on heat and mass transfer in salt finger convection within a micropolar liquid layer confined between two infinitely long, parallel plates separated by a thin gap. The system is heated and soluted from above. A linear and nonlinear stability analysis is carried out to investigate the heat and mass transfer mechanisms in the presence of magnetic field. A linear stability analysis is conducted to determine the critical Rayleigh number and solutal Rayleigh number, which are key parameters governing the onset of salt finger convection. To model the system, the governing nonlinear partial differential equations are solved numerically using finite-amplitude analysis. The solution framework utilizes a Fourier series representation of the stream function, spin, magnetic field, temperature distribution, and concentration distribution. The study further explores the influence of various micropolar fluid parameters such as the coupling parameter, micropolar heat conduction parameter, couple stress parameter, and inertia parameter on heat and mass transfer under magnetic field effects. To provide deeper physical insight, flow variables are analyzed and illustrated graphically for different values of micropolar parameters over time. Finally, the paper presents key findings and their implications in the results and discussions.</p>