A hydraulic control system for a work machine including: a hydraulic actuator; a first hydraulic pump and a second hydraulic pump capable of communicating with the hydraulic actuator; a first directional control valve that is disposed in a pump line communicating with a delivery port of the first hydraulic pump and communicates with the hydraulic actuator, the first directional control valve capable of interrupting a communication between the first hydraulic pump and the hydraulic actuator and returning a hydraulic fluid delivered by the first hydraulic pump to a tank; a second directional control valve that is disposed in a pump line communicating with a delivery port of the second hydraulic pump and communicates with the hydraulic actuator; and a first pressure sensor that detects a load on the hydraulic actuator, characterized by a pressure reducing valve that is provided in a pilot line (AmC) connected with the first directional control valve and limits or interrupts a pilot hydraulic fluid to be supplied to the first directional control valve; a communication control section that takes in a detection signal detected by the first pressure sensor, outputs a command signal to the pressure reducing valve and drives the first directional 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 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 hydraulic actuator, takes in a detection signal detected by the first pressure sensor and controls to reduce a delivery flow rate of the first hydraulic pump corresponding to an increase in the load on the hydraulic actuator. a hydraulic actuator; a first hydraulic pump and a second hydraulic pump capable of communicating with the hydraulic actuator; a first directional control valve that is disposed in a pump line communicating with a delivery port of the first hydraulic pump and communicates with the hydraulic actuator, the first directional control valve capable of interrupting a communication between the first hydraulic pump and the hydraulic actuator and returning a hydraulic fluid delivered by the first hydraulic pump to a tank; a second directional control valve that is disposed in a pump line communicating with a delivery port of the second hydraulic pump and communicates with the hydraulic actuator; and a first pressure sensor that detects a load on the hydraulic actuator, characterized by a pressure reducing valve that is provided in a pilot line (AmC) connected with the first directional control valve and limits or interrupts a pilot hydraulic fluid to be supplied to the first directional control valve; a communication control section that takes in a detection signal detected by the first pressure sensor, outputs a command signal to the pressure reducing valve and drives the first directional 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 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 hydraulic actuator, takes in a detection signal detected by the first pressure sensor and controls to reduce a delivery flow rate of the first hydraulic pump corresponding to an increase in the load on the hydraulic actuator.