An accessory gear train layout structure at the front end of an automobile engine comprises a crankshaft pulley, an automatic tensioning pulley, an alternating-current generator belt pulley, an idler pulley, a water pump belt pulley, an air conditioner compressor belt pulley and a multi-wedge belt. The gear train only contains single-layer gear trains, and the air conditioner compressor belt pulley and the water pump belt pulley are respectively arranged on the same side of the crankshaft pulley and close to the side of an exhaust manifold; the alternating-current generator belt pulley is arranged above the crankshaft pulley and close to the side of an inlet manifold; the air conditioner compressor belt pulley and the alternating-current generator belt pulley are arranged on the two sides of the crankshaft pulley respectively; the automatic tensioning pulley is located between the crankshaft pulley and the alternating-current generator belt pulley; the idler pulley is located between the alternating-current generator belt pulley and the water pump belt pulley. The accessory gear train layout structure at the front end of the automobile engine meets the requirement of a condition machine through which a finished automobile selects or does not select air conditioner compression, the cost of the engine and the requirement for compact size of the finished machine are also taken into consideration, and a series of waste of manpower and development expenses caused by changes of an accessory gear train system at the front end is greatly reduced.