A flow rate control apparatus for construction equipment, the apparatus comprising: first and second variable displacement hydraulic pumps and a pilot pump; a boom cylinder driven by a hydraulic fluid of the first hydraulic pump; a first control valve controlling a flow of the hydraulic fluid supplied from the first hydraulic pump to the boom cylinder; an option actuator driven by a hydraulic fluid of the second hydraulic pump; a second control valve controlling a flow of the hydraulic fluid supplied from the second hydraulic pump to the option actuator; a boom cylinder manipulation lever for inputting a manipulation signal to control the first control valve, and an option actuator manipulation lever for inputting a manipulation signal to control the second control valve; a confluence line connected at an inlet port thereof to a downstream side of a supply path of the first hydraulic pump, and connected at an outlet port thereof to a meter-in port of the second control valve; characterized in that the flow rate control apparatus comprises: a center bypass switching valve provided in the furthest downstream side of the supply path of the first hydraulic pump, and operated to close an opening port thereof by a pilot pressure applied thereto; a confluence switching valve provided in the confluence line, and joining a part of the hydraulic fluid supplied from the first hydraulic pump to the boom cylinder with the hydraulic fluid of the option actuator when the confluence switching valve is operated to open an opening port thereof; a confluence selection valve provided in a fluid path between the pilot pump and the confluence switching valve, and applying the pilot pressure to the confluence switching valve when the confluence switching valve is operated; and a controller controlling the confluence selection valve to block the pilot pressure supplied from the pilot pump to the confluence switching valve so that the confluence line becomes closed when combined work of the boom cylinder and the option actuator is performed. first and second variable displacement hydraulic pumps and a pilot pump; a boom cylinder driven by a hydraulic fluid of the first hydraulic pump; a first control valve controlling a flow of the hydraulic fluid supplied from the first hydraulic pump to the boom cylinder; an option actuator driven by a hydraulic fluid of the second hydraulic pump; a second control valve controlling a flow of the hydraulic fluid supplied from the second hydraulic pump to the option actuator; a boom cylinder manipulation lever for inputting a manipulation signal to control the first control valve, and an option actuator manipulation lever for inputting a manipulation signal to control the second control valve; a confluence line connected at an inlet port thereof to a downstream side of a supply path of the first hydraulic pump, and connected at an outlet port thereof to a meter-in port of the second control valve; characterized in that the flow rate control apparatus comprises: a center bypass switching valve provided in the furthest downstream side of the supply path of the first hydraulic pump, and operated to close an opening port thereof by a pilot pressure applied thereto; a confluence switching valve provided in the confluence line, and joining a part of the hydraulic fluid supplied from the first hydraulic pump to the boom cylinder with the hydraulic fluid of the option actuator when the confluence switching valve is operated to open an opening port thereof; a confluence selection valve provided in a fluid path between the pilot pump and the confluence switching valve, and applying the pilot pressure to the confluence switching valve when the confluence switching valve is operated; and a controller controlling the confluence selection valve to block the pilot pressure supplied from the pilot pump to the confluence switching valve so that the confluence line becomes closed when combined work of the boom cylinder and the option actuator is performed. a center bypass switching valve provided in the furthest downstream side of the supply path of the first hydraulic pump, and operated to close an opening port thereof by a pilot pressure applied thereto; a confluence switching valve provided in the confluence line, and joining a part of the hydraulic fluid supplied from the first hydraulic pump to the boom cylinder with the hydraulic fluid of the option actuator when the confluence switching valve is operated to open an opening port thereof; a confluence selection valve provided in a fluid path between the pilot pump and the confluence switching valve, and applying the pilot pressure to the confluence switching valve when the confluence switching valve is operated; and a controller controlling the confluence selection valve to block the pilot pressure supplied from the pilot pump to the confluence switching valve so that the confluence line becomes closed when combined work of the boom cylinder and the option actuator is performed.