A hydraulic control device for a work machine, comprising: a prime mover; a hydraulic pump of the variable displacement type which is driven by the prime mover; a hydraulic actuator which is driven by hydraulic fluid delivered from the hydraulic pump; a directional control valve which controls the flow of the hydraulic fluid supplied from the hydraulic pump to the hydraulic actuator; a control lever unit through which an operator inputs operation commands; an operation amount detector (20A, 20B) which detects the operation amount of the control lever unit; a pressure detector which detects the delivery pressure of the hydraulic pump; and a pump control device (6, 2a; 6A, 2a; 6B, 2aA, 62, 63) which controls a tilt amount of the hydraulic pump, characterized in that the pump control device (6, 2a; 6A, 2a; 6B, 2aA, 62, 63) includes: a target pump pressure setting unit (32; 32A; 32B) which calculates a target pump delivery pressure which increases with the increase in an operation amount signal from the operation amount detector (20A, 20B) based on the operation amount signal from the operation amount detector (20A, 20B 1); a pump flow rate upper limit setting unit (33; 33A) which calculates a pump flow rate upper limit which increases with the increase in the operation amount signal from the operation amount detector (20A, 20B) based on the operation amount signal from the operation amount detector (20A, 20B); and a tilt amount control unit (34, 35, 37, 2a; 2aA) which controls the tilt amount of the hydraulic pump based on the target pump pressure calculated by the target pump pressure setting unit (32; 32A; 32B), the pump flow rate upper limit calculated by the pump flow rate upper limit setting unit (33; 33A) and the delivery pressure of the hydraulic pump detected by the pressure detector. a prime mover; a hydraulic pump of the variable displacement type which is driven by the prime mover; a hydraulic actuator which is driven by hydraulic fluid delivered from the hydraulic pump; a directional control valve which controls the flow of the hydraulic fluid supplied from the hydraulic pump to the hydraulic actuator; a control lever unit through which an operator inputs operation commands; an operation amount detector (20A, 20B) which detects the operation amount of the control lever unit; a pressure detector which detects the delivery pressure of the hydraulic pump; and a pump control device (6, 2a; 6A, 2a; 6B, 2aA, 62, 63) which controls a tilt amount of the hydraulic pump, a target pump pressure setting unit (32; 32A; 32B) which calculates a target pump delivery pressure which increases with the increase in an operation amount signal from the operation amount detector (20A, 20B) based on the operation amount signal from the operation amount detector (20A, 20B 1); a pump flow rate upper limit setting unit (33; 33A) which calculates a pump flow rate upper limit which increases with the increase in the operation amount signal from the operation amount detector (20A, 20B) based on the operation amount signal from the operation amount detector (20A, 20B); and a tilt amount control unit (34, 35, 37, 2a; 2aA) which controls the tilt amount of the hydraulic pump based on the target pump pressure calculated by the target pump pressure setting unit (32; 32A; 32B), the pump flow rate upper limit calculated by the pump flow rate upper limit setting unit (33; 33A) and the delivery pressure of the hydraulic pump detected by the pressure detector.