The invention relates to a large-power LED constant-current driving power supply, and belongs to the technical field of LED constant-current driving power supplies. The large-power LED constant-current driving power supply comprises a power chip, a protection shell, an installation shell, an adjustment mechanism, a cooling mechanism and an automatic power-failure mechanism, wherein the power chipis arranged in the protection shell, an installation cavity is formed in the installation shell, an installation door is arranged at one side of the installation shell, the protection shell is arranged in the installation shell, the protection shell and the installation shell are fixedly connected by the adjustment mechanism, the cooling mechanism is arranged at an upper end of the installation shell, the automatic power-failure mechanism is arranged in the installation shell, the cooling mechanism comprises a lifting assembly and a cycle cooling assembly, and the cycle cooling assembly is connected with the lifting assembly. With the arrangement of the protection shell and the installation shell, the power chip can be rapidly disassembled and replaced, and the maintenance speed is improved; by arranging the adjustment mechanism, different types of power chips can be replaced, and maintenance operation is convenient; and by arranging the automatic power-failure mechanism, the equipmentsafety can be protected, and an accident is prevented.