A hydraulic circuit system for construction equipment, the hydraulic circuit system comprising: a hydraulic pump and a pilot pump ; a hydraulic cylinder driven by hydraulic fluid supplied by the hydraulic pump ; a directional control valve disposed on a path between the hydraulic pump and the hydraulic cylinder to control a flow of hydraulic fluid supplied to and discharged from the hydraulic cylinder ; a control device disposed on a path between the pilot pump and the directional control valve to output a control signal to control the directional control valve ; a central bypass control valve disposed farthest downstream of a central bypass passage connected to the hydraulic pump , the central bypass control valve being switched to close an opening of a passage thereof when receiving pilot pressure applied by the control device ; a pressure sensor detecting hydraulic pressure of hydraulic fluid on a large chamber side of the hydraulic cylinder ; and a jack-up control valve disposed on a path between the control device and the central bypass control valve , the jack-up control valve switched to allow the control device to apply the pilot pressure to the central bypass control valve when receiving a first electrical signal; characterized in that a flow control valve is disposed in the directional control valve , wherein, in a retraction operation of the hydraulic cylinder , the flow control valve is switched to an on position to block a flow of hydraulic fluid from the hydraulic pump to a small chamber of the hydraulic cylinder when the hydraulic pressure of hydraulic fluid on the large chamber side exceeds a preset pressure and is switched to open an opening thereof to allow the flow of hydraulic fluid from the hydraulic pump to the small chamber of the hydraulic cylinder when the hydraulic pressure of hydraulic fluid on the large chamber side is equal to or lower than the preset pressure. a hydraulic pump and a pilot pump ; a hydraulic cylinder driven by hydraulic fluid supplied by the hydraulic pump ; a directional control valve disposed on a path between the hydraulic pump and the hydraulic cylinder to control a flow of hydraulic fluid supplied to and discharged from the hydraulic cylinder ; a control device disposed on a path between the pilot pump and the directional control valve to output a control signal to control the directional control valve ; a central bypass control valve disposed farthest downstream of a central bypass passage connected to the hydraulic pump , the central bypass control valve being switched to close an opening of a passage thereof when receiving pilot pressure applied by the control device ; a pressure sensor detecting hydraulic pressure of hydraulic fluid on a large chamber side of the hydraulic cylinder ; and a jack-up control valve disposed on a path between the control device and the central bypass control valve , the jack-up control valve switched to allow the control device to apply the pilot pressure to the central bypass control valve when receiving a first electrical signal; characterized in that a flow control valve is disposed in the directional control valve , wherein, in a retraction operation of the hydraulic cylinder , the flow control valve is switched to an on position to block a flow of hydraulic fluid from the hydraulic pump to a small chamber of the hydraulic cylinder when the hydraulic pressure of hydraulic fluid on the large chamber side exceeds a preset pressure and is switched to open an opening thereof to allow the flow of hydraulic fluid from the hydraulic pump to the small chamber of the hydraulic cylinder when the hydraulic pressure of hydraulic fluid on the large chamber side is equal to or lower than the preset pressure. <EOS>