The bill detector is a compact, portable financial verification device designed for fast and reliable banknote authenticity checking. Widely used in bank counters, retail shops, restaurants, hotels, gas stations and various cash-handling premises, it provides instant fake-note screening for daily cash transactions. Equipped with multi-sensors including ultraviolet(UV), magnetic(MG), infrared(IR), White Light(WL) and image scanning modules, the detector identifies multiple security features of banknotes. It can spot counterfeit, altered, forged and suspicious banknotes efficiently. Light-weight and space-saving, this bill detector supports both mains power and optional battery power supply for flexible deployment. Simple-to-operate design requires minimal training for staff. No complicated setting is needed; users can start verification right after power-on. Supporting multiple global currencies, the device can be updated via USB interface to adapt for newly-issued banknote versions. Durable housing structure ensures long-term daily-use reliability. As a cost-effective anti-counterfeiting tool, it delivers quick, convenient banknote authentication for small-to-medium size businesses and financial service sites.