A light-mixing multichip package structure includes a substrate unit, a light-emitting unit, a package unit, and a frame unit. The substrate unit includes a substrate body. The light-emitting unit includes a plurality of first and second light-emitting groups. The first and the second light-emitting groups are disposed on the substrate body and electrically connected to the substrate body in series. Each first light-emitting group includes a plurality of first parallel connection units electrically connected in parallel, and each first parallel connection unit includes at least one blue LED chip, and each second light-emitting group includes at least one red LED chip. The package unit includes a phosphor resin body disposed on the substrate body to cover the first and the second light-emitting groups. The frame unit includes a surrounding light-reflecting frame surrounding the first and the second light-emitting groups and the phosphor resin body.