Abstract: Hydraulic system for actuating the hydraulic actuators of a working machine, the hydraulic system has a delivery, a discharge, a drainage line, a signal line, a main slide valve which actuates a corresponding hydraulic actuator, a safety slide valve integral with the main slide valve and adapted for opening or closing the drainage line itself, and a pressure compensator presenting a frontal chamber connectable by way of the main slide valve to the delivery and a rear chamber connected to the signal line; the drainage line connecting a node of the signal line to the discharge.