Independent photoelectric smoke fire detection alarm (hereinafter referred to as alarm) can detect smoke generated during fire and send out alarm signals in time. The alarm adopts photoelectric smoke sensing devices and excellent production technology, with stable operation and beautiful appearance. The alarm is powered by 3V battery, with low power consumption, self-test function and battery undervoltage prompt function. It is suitable for various indoor places such as homes, schools, nursing homes, guesthouses, hotels, factories, etc. that need fire safety alarm monitoring, and is used to detect fire smoke generated by wood, cotton fabrics, plastics and hydrocarbons.