The invention provides a milling-grinding compound machine tool which comprises a workpiece clamping mechanism and a cutter clamping mechanism. The cutter clamping mechanism comprises a positioning shaft, wherein the positioning shaft is further provided with a rotary driving mechanism and is sleeved with a cutter disc, the cutter disc is provided with at least two cutter moving slots, and a cutter comprises at least one set of milling cutters and at least one set of grinding cutters. Cutter pushing-lifting mechanisms are arranged in the cutter moving slots and are provided with cutter locking/automatic unlocking mechanisms, cutter resetting mechanisms are arranged in the cutter moving slots, and the cutter pushing-lifting mechanisms are provided with slippage guide rail mechanisms and pushing-lifting slippage driving mechanisms. A cutter catching mechanism is arranged on the positioning shaft. A machining device is further provided with an image detection unit and a temperature detection unit. The milling-grinding compound machine tool has the advantages that the milling cutters and the grinding cutters are installed on the same machine tool for compound machining, and multiple sets of cutters are internally hidden in the cutter disc and are safe in use; the arranged image detection unit can remotely observe the machining process in real time.