Wi-Fi Network Interface Cards (NICs) are vital for enabling wireless connectivity across a wide range of devices. Ensuring their security is critical, as vulnerabilities can expose entire networks to threats. Fuzzing is a promising technique for detecting such flaws. However, existing Wi-Fi fuzzers typically test transmission and reception separately, overlooking their interactions and resulting in inefficient testing.In this work, we present DualFuzz, a dual-directional fuzzing framework designed to simultaneously test both transmission and reception processes in Wi-Fi NICs. First, DualFuzz automatically identifies interaction behaviors within Wi-Fi NICs and constructs a Transmission-Reception Model (TRModel) to characterize Wi-Fi frames that influence these interactions. Leveraging this model, DualFuzz utilizes latency guided fuzzing to efficiently coordinate exploring transmission and reception interaction logics. Finally, we propose liveness and equivalence detectors that enable real-time monitoring to identify abnormal states and uncover potential vulnerabilities in Wi-Fi NICs. We implemented and evaluated DualFuzz on eight widely used Wi-Fi NICs, incorporating chipsets from various manufacturers (e.g., Intel and Realtek). Compared to state-of-the-art Wi-Fi fuzzers like OwFuzz, wpaspy, and Greyhound, DualFuzz detects 75%, 163%, and 250% more vulnerabilities, respectively. In total, it uncovered 21 previously unknown vulnerabilities, 7 of which have been assigned CVEs.