We consider the load-balancing design for forwarding incoming flows to access points (APs) in high-density wireless networks with both channel fading and flow-level dynamics, where each incoming flow has a certain amount of service demand and leaves the system once its service request is complete. The efficient load-balancing design is strongly needed for supporting high-quality wireless connections in high-density areas. In this work, we propose a Joint Load-Balancing and Scheduling (JLBS) Algorithm that always forwards the incoming flows to the AP with the smallest workload in the presence of flow-level dynamics and each AP always serves the flow with the best channel quality. Our analysis reveals that our proposed JLBS Algorithm not only achieves maximum system throughput, but also minimizes the total system workload in the heavy-traffic regime. Moreover, we observe from both our theoretical and simulation results that the mean totalworkload performance under the proposed JLBS Algorithm does not degrade as the number of APs increases, which is strongly desirable in high-density wireless networks.