Maintaining macroscopic ferroelectric polarization in the polycrystalline state is always challenging, due to the random orientation of polar axes. This directly leads to reported perovskite polycrystalline wafer X-ray detectors still rely on external voltage bias, resulting in high energy consumption and limiting integration potential, though the simply-prepared polycrystalline wafers are promising candidates for advanced X-ray detection. Here, oriented ferroelectric wafers made of two-dimensional biaxial perovskite ferroelectric EA₄Pb₃Br₁₀ (EA = ethylamine) were acquired, enabling self-driven X-ray detection. The EA₄Pb₃Br₁₀ ferroelectric wafer exhibits well-oriented (0k0) planes, with four equivalent polarization directions distributed, leading to macroscopic spontaneous polarization in the polycrystalline state. Consequently, a switchable open-circuit voltage of 0.30 V was obtained under the irradiation, enabling impressive self-driven X-ray detection performance, including a remarkable sensitivity of 203.3 μC·Gy⁻¹·cm⁻², a low detection limit of 17 nGy·s⁻¹, and great operational reliability. The sensitivity further reaches a high value of 3779.2 μC·Gy⁻¹·cm⁻² at 100 V·mm⁻¹, which surpassed many reported perovskite polycrystalline wafers. To our knowledge, this work represents the first realization of self-driven X-ray detection in the perovskite wafer family, offering an available strategy for the simple acquisition of self-driven radiation detectors.