Electromagnetic levitation control is a core technology for ensuring the stable operation of maglev trains. To enhance the disturbance rejection capability and stability of the levitation system, an IWOA-ISMC control strategy is proposed in this paper. First, a single-electromagnet levitation model with two degrees of freedom is established, in which the effects of spring stiffness and damping are taken into account. Based on this model, an integral sliding mode controller (ISMC) is designed. However, manual parameter tuning based on engineering experience makes it difficult to obtain an optimal parameter combination, and inappropriate controller parameters may lead to significant performance degradation. To address this issue, an improved whale optimization algorithm (IWOA) is introduced to globally optimize the key parameters of the ISMC, resulting in an IWOA-ISMC tailored to the proposed model. Comparative simulations under track irregularity conditions and sudden force disturbances induced by track irregularities are conducted. The results demonstrate that, compared with ISMC, PID, and backstepping controllers, the proposed IWOA-ISMC approach exhibits superior disturbance rejection performance and robustness.