The internal structure of fast recovery diode is different from that of ordinary diode. It adds base region I between P-type and N-type silicon materials to form P-I-N silicon wafer. Because the base region is very thin and the reverse recovery charge is very small, not only the trr value is greatly reduced, but also the transient forward voltage drop is reduced, so that the tube can withstand high reverse working voltage. The reverse recovery time of fast recovery diode is generally several hundred nanoseconds, the forward voltage drop is about 0.6V, the forward current is several amperes to several thousand amperes, and the reverse peak voltage can reach several hundred to several thousand volts.