The present application discloses a semiconductor light-emitting device with a protection layer. The structure includes a heat dispersion substrate, a first connecting layer on the heat dispersion substrate, a protection layer on the first connecting layer, a second connecting layer on the protection layer, and a light-emitting unit on the second connecting layer. The protection layer is highly insulative and can avoid the current leakage forming between the light-emitting unit and the heat dispersion substrate.