The invention discloses a silica-based forward implantation light-emitting device and a manufacturing method thereof. The device comprises a P-shaped silicon substrate, an N-well, a U-shaped comb structure, a P+ heavy doping active region, an SiO2 gate oxide layer, a polysilicon gate, wherein the N-well is embedded in the P-shaped silicon substrate; the U-shaped comb structure is formed from alternate N+ heavy doping active region and P+ heavy doping active region; the section plane of the U-shaped comb structure is the N+-P+-P+-P+-N+-P+-P+-P+-N+-P+-P+-P+-N+-P+-P+-P+-N+ structure; the U-shaped comb structure is embedded in the N-well; the P+heavy doping active region is positioned on the periphery of the N-well and is embedded in the P-shaped silicon substrate to form a P+substrate contact; the SiO2 gate oxide layer is positioned above among the P+-P+ of the device; the polysilicon gate is positioned on the SiO2 gate oxide layer and has a strip U-shaped structure; the N+heavy doping active region is connected with the cathode by the metal; and the P+heavy doping active region in the well, the polysilicon gate among the P+ and the P+substrate contact outside the N-well are connected with an extraction anode by the metal. The PN junction forward light emitting is realized by utilizing the invention and adopting the P-shaped substrate and the P+heavy doping active region in the N-well to carry out double implantation on the cathode.