The invention discloses a hydraulic system for engineering machinery and an excavator. The hydraulic control system comprises a controller, a pump assembly and an equipment control loop. The pump assembly communicates with the equipment control loop so as to output hydraulic oil with hydraulic energy to the equipment control loop. The equipment control loop comprises a connection pipe capable of being connected with hydraulic equipment, and the equipment control loop can perform speed regulation and/or pressure regulation on the hydraulic oil which is output by the pump assembly and provided with the hydraulic energy. The controller is connected with the equipment control loop, can obtain the pressure of the hydraulic oil in the connection pipe and control the output flow of the pump assembly according to the pressure of the hydraulic oil in the output pipe. By means of the technical scheme, the equipment control loop can perform speed regulation and/or pressure regulation on the hydraulic oil which is output by the pump assembly and provided with the hydraulic energy, fine operation of a self-controlled multifunctional small-sized hand-held hydraulic tool can be realized, intelligent control over the hydraulic system is facilitated, and thus fuel economy is realized.