The invention provides an energy-saving hydraulic control system for a work machine including a specific actuator that can supply a hydraulic fluid from a plurality of hydraulic pumps. The hydraulic control system for a work machine includes: a first hydraulic pump and a second hydraulic pump capable of communicating with a first hydraulic actuator; a first control valve capable of returning a hydraulic fluid delivered by the first hydraulic pump to a tank; and a load detection section that detects a load on the first hydraulic actuator. The hydraulic control system includes: a control valve drive section that drives the first control valve such that a communication area between the first hydraulic pump and the tank is enlarged corresponding to an increase in the load on the first hydraulic actuator; and a flow rate control section that, during supply of the hydraulic fluid from the first hydraulic pump and the second hydraulic pump to the first hydraulic actuator, controls to reduce a delivery flow rate of the first hydraulic pump corresponding to an increase in the load on the first hydraulic actuator.