The invention provides a quick power-down signal detection circuit and a power-on reset device for detecting power supply voltage jitter. The quick power-down signal detection circuit includes: an edge generating circuit which is used for sensing voltage jitter of a power supply and generating a peak signal; a quick power-down signal generation circuit which is used for receiving the peak signal and outputting a quick power-down signal, wherein the quick power-down signal generation circuit comprises a latch, wherein an output point of the falling edge signal is connected to an Ns point of a grid electrode of a first-stage phase inverter of the latch through a capacitor C6, an output point of the rising edge signal is connected to an s point output by the first-stage phase inverter of thelatch through a capacitor C5, and the Ns point outputs the fast power-down signal. Through power supply voltage jitter detection, an effective long-time reset signal is generated, and 10ns-level powerfailure detection can be realized at the soonest.