The invention discloses an AlGaInP red light-emitting diode device structure with a composite reflector. The reflector of a conventional AlGaInP red light-emitting diode is changed into a composite reflector layer, the composite reflector layer is divided into a reflection area, an electrode and an adhesion area, the reflection area consists of a dielectric layer and a reflection metal, the refractive index of the dielectric material of the dielectric layer is between 1.0 and 2.5, the electrode is metal, the material is related to a contacted semiconductor material, for p-type GaP, the metal material of the electrode is Au or AuZn alloy or stacking layer of Au and AuZn alloy, or, the metal material of the electrode is Ag or NiAg stacking layer or TiAg stacking layer; for n-type GaAs, the metal material of the electrode is a stacking layer of three metals such as Ni, Au and Ge or alloy of two or more than two of Ni, Au and Ge; and the adhesion material of the adhesion area is one of Cr,Ti, Ni, Mg, Fe and TiW. The AlGaInP red light-emitting diode device structure has the advantages that the reflection rate of the reflector and the light outgoing efficiency and electro-optical conversion efficiency of the device are improved and simultaneously the reflector structure has preferable adhesion and reliability.