Due to the limited electrode structure types of current CH 3 NH 3 PbCl 3 perovskite single crystal photodetectors, these devices either have good performance but small active area or have large active area but poor performance, which greatly limits their applications. To realize a high performance of a CH 3 NH 3 PbCl 3 perovskite single crystal photodetector with a large active area, a CH 3 NH 3 PbCl 3 single crystal photodetector with asymmetrical Schottky interdigital contacts originating from planar interdigital Au-Ag electrodes was fabricated in this work. The device not only had a large active area (around 8 mm 2 ) but also showed excellent photoelectric performance due to its built-in electric field. The responsivity of the device can reach 5.8 mA W -1 at 0 V and 0.24 A W -1 at 30 V reverse voltage. The response time of the device can reach 317 μs (rise)/6.82 ms (decay) at 0 V and 100 μs (rise)/2 ms (decay) at 30 V reverse voltage. The above results demonstrate that this study will provide an effective method for realizing high performance of a CH 3 NH 3 PbCl 3 perovskite single crystal photodetector with a large active area.