Abstract: The paper primarily investigates the thermodynamic properties of isospin-asymmetric quark matter realized by both scalar interactions and instanton-induced interactions within the Nambu Jona-Lasinio (NJL) model under strong magnetic fields. The research findings are as follows: When the isospin chemical potential is zero, the dynamical masses of quarks in the isospin-asymmetric state are distributed on both sides of the dynamical masses in the isospin-symmetric state, and the larger charge of the u quark results in a greater dynamical mass. Both the peak position of the specific heat capacity and the location of the regional minimum of the sound velocity can indicate the critical temperature of the chiral first-order phase transition and the pseudo-critical temperature of the crossover transition. At low temperatures, low densities, and moderate magnetic field strengths, for the isospin-symmetric state, a smaller chemical potential corresponds to lower quark dynamical masses and a reduced average baryon free energy, indicating that the quark matter is more stable in the chiral symmetry broken phase than in the chiral symmetry restored phase.