The invention relates to a coiled tubing well drilling underground tool, in particular to a mechanical system of a coiled tubing electro-hydraulic machine control orienting tool. According to the mechanical system, an upper joint, an anti-twisting sleeve, a connecting sleeve, an oil flow channel tube body III, a piston sleeve, a mandrel sleeve and a bearing sleeve are connected in sequence. A channel is formed in the center of an oil flow channel tube body I. The tube wall of the oil flow channel tube body I and the tube wall of an oil flow channel tube body II are respectively provided with two flow channels. Plunger installation holes are formed in the upper ends of the two flow channels of the oil flow channel tube body I and the upper ends of the two flow channels of the oil flow channel tube body II respectively. The oil flow channel tube body I is connected with the oil flow channel tube body II and the two flow channels of the oil flow channel tube body I are communicated with the two flow channels of the oil flow channel tube body II respectively. According to the mechanical system of the coiled tubing electro-hydraulic machine control orienting tool, the drilling directions and well tracks of a coiled tubing drilling-side drilled well, a side-drilled horizontal well and the like can be accurately and reliably controlled and the shortages that an existing orienting tool is low in accuracy and poor in controllability are overcome.