The invention discloses a stone carving machine with a carving knife depth convenient to adjust. The stone carving machine with the carving knife depth convenient to adjust comprises a carving machinebody. A control arm of the carving machine body is connected with a carving tool. The carving tool comprises a control arm connecting rod, a carving knife size adjusting rod, a carving knife connecting rod and a carving knife. The control arm connecting rod and the carving knife connecting rod are connected to the two ends of the carving knife size adjusting rod through threads correspondingly. The carving knife size adjusting rod is provided with an external thread in a surrounded manner. The outer side of the carving knife size adjusting rod is provided with a first rotating hole. The outerside of the carving knife connecting rod is provided with a second rotating hole. The first rotating hole and the second rotating hole are provided with a rotary operating rod. The carving knife sizeadjusting rod is provided with scales. According to the stone carving machine with the carving knife depth convenient to adjust, the depth of the carving tool can be flexibly and precisely adjusted through the length, the tedious steps of carving knife changing are reduced, adjusting is easy and convenient, and the working efficiency of the stone carving machine can be greatly improved.