The invention discloses a compact multi-mode valve driving system and belongs to the field of engine valve driving, stroke changing and auxiliary braking. The compact multi-mode valve driving system comprises a first cam shaft provided with a shaft sleeve, a second cam shaft provided with an exhaust braking cam, switching assemblies, a braking switch and the like. The shaft sleeve is provided with an intake four-stroke cam, an intake two-stroke cam, an exhaust four-stroke cam, an exhaust two-stroke cam and two switching grooves. The axial position of the shaft sleeve is controlled through the two switching assemblies, and two-stroke and four-stroke seamless switching is achieved; and the driving modes and the braking modes are switched through only one braking switch. By means of the compact multi-mode valve driving system, the four modes including the four-stroke driving mode, the two-stroke driving mode, the four-stroke braking mode and the two-stroke braking mode are flexibly switched, and high-power, low-oil-consumption, low-emission and efficient graded braking is achieved. The compact multi-mode valve driving system is simple and compact in structure, high in reliability, low in cost and high in response speed.