The invention discloses a high stable enhanced colour rendering LED light source module, comprising a base plate and a mixed light cavity arranged at the edge of the base plate; the mixed light cavityis internally provided with a white light LED chip, a colour LED chip and a light sensor, the mixed light cavity is internally filled with a first euphotic medium, the light outlet of the mixed lightcavity is provided with a second euphotic medium, the inner wall of the mixed light cavity and the lower surface of the second euphotic medium form a multiple reflection cavity; the colour LED chip is also connected with a control circuit, the light sensor can detect white light luminous flux in the mixed light cavity, and the control circuit can regulate luminous flux of the colour LED chip according to the detection result of the light sensor. The module can provide high colour rendering light output while keeping lighting effect, colour temperature is extremely steady; and light can be fully mixed, and bright dipping can be uniform. The manufacture technology of the module also has great flexibility and consistency.