The utility model provides a digital human body infrared receiving and processing circuit, which comprises a passive infrared radiation (PIR) sensor circuit, a sensing signal amplifying circuit of the PIR sensor circuit, an output driving circuit and a power source voltage stabilizing circuit. The digital human body infrared receiving and processing circuit is characterized in that a microprocessor circuit adopting a microprocessor chip of a 11-bit and 4-bit analog/digital (AD) converter, a photosensitive sensor circuit, a jumper wire on which a lamp lighting duration time is set, and a power source voltage detecting circuit are arranged in the digital human body infrared receiving and processing circuit; PIR analog signals are amplified and then digitally processed by the microprocessor chip, wherein the digital processing includes the steps that the PIR analog signals are subjected to A/D conversion into digital signals and then useful signals are recognized by using software embedded into the microprocessor chip; and logic control is realized by input information of voltage signals converted from strength signals of external light by the photosensitive sensor, switch level signals formed by short connection and disconnection of the jumper wire on which the lamp lighting duration time is set, and output voltages of the power source voltage detecting circuit. Not only is the circuit structure simplified, but the sensitivity and the reliability of the circuit are improved.