Hydraulic system of overflow-loss-free loader and control method of hydraulic system

The invention discloses a hydraulic system of an overflow-loss-free loader and a control method of the hydraulic system. On the basis of an original hydraulic system of the loader, parts like energy accumulators, reversing valves, sensors and a controller are additionally mounted, and part simplification is performed; through corresponding control strategies, matching between output flow of a fixed displacement pump and needed flow of a load (an external load and the energy accumulator) can be realized, overflow loss can be avoided completely, and throttling loss and friction loss can be reduced; potential energy recycled is used for being provided to a steering gear, a multi-pump hydraulic system of the loader is changed into a single-pump hydraulic system, and energy is stored through the energy accumulator, so that pressure buildup time of the hydraulic system and installed power of an engine are reduced, and efficiency of the whole loader is improved. The energy accumulator is utilized to absorb pressure impact, so that stability and reliability of the hydraulic system are improved while fatigue lives of elements are prolonged.