The invention provides an engine test bench and a crankshaft front-end output test device to verify the use reliability of engines and avoid the occurrence of shaft breakage, bush eccentric wear, and the like. The test device comprises a first dynamometer and a connecting shaft. One end of the connecting shaft is in transmission connection with the crankshaft front end of an engine through a belt, and the other end is connected with the first dynamometer. The first dynamometer applies a load to the crankshaft front end through the connecting shaft to simulate the load output by the crankshaft front end. The test device of the invention can be used to simulate the operation condition of the front end of the engine truly and effectively to verify the reliability of the front-end output of the engine. As the output power and torque of the crankshaft front end can be acquired through the first dynamometer directly, and the output of the crankshaft front end is simulated, the maximum belt tension and the minimum belt tension can be acquired, and therefore, data support is provided for engine performance optimization and entire vehicle matching.