The invention relates to a power device and a manufacturing method of the power device, in particular to a fast recovery diode chip of a low-concentration doped emitter region and a manufacturing method of the fast recovery diode chip of the low-concentration doped emitter region. The fast recovery diode chip of the low-concentration doped emitter region comprises a metal cathode, a metal anode, a P-type doped layer, an N-type doped layer, an N-type substrate arranged between the P-type doped layer and the N-type doped layer, field oxide layers and passivation protective layer structures, wherein the metal anode is a low-concentration P-type doped region, the metal cathode is a low-concentration N-type buffer doped region and a low-concentration N-type reinforced doped region, the special manufacturing mode of injection doped of the reverse side is formed through an obverse side protection technology, and a device structure is formed through the special manufacturing mode of injection doped of the reverse side. According to the fast recovery diode chip of the low-concentration doped emitter region and the manufacturing method of the fast recovery diode chip of the low-concentration doped emitter region, due to the fact that the doped concentration of an anode emitter region and the doped concentration of a cathode emitter region are reduced, the self-key electric potential difference of a PN-junction is reduced, the total number of injection holes of the P-type doped region is reduced, performance of a fast recovery diode is integrally optimized, it is ensured that the fast recovery diode has low forward communication voltage drop, and the dynamic performance of a device is improved.