Space-Air-Ground Integrated Network (SAGIN) is a crucial component of 6G technology. SAGIN offers a promising solution for Internet of Things (IoT) applications in areas lacking ground network coverage. In data acquisition scenarios, multiple types of IoT devices are utilized to collect diverse data, leading to varying and time-sensitive channel capacity requirements. However, effectively and fairly allocating resources to different IoT device categories based on dynamic requirements remains a challenge. This paper formulates a multi-objective optimization problem to maximize the minimum link capacity for various categories of IoT devices. To solve this non-convex problem, we propose an improved multi-objective evolutionary algorithm for the multi-party fair allocation of resources. It optimizes the deployment location of the UAV and the bandwidth allocation for IoT devices. Comparative analysis against classical algorithms validates the superior performance of the proposed algorithm.