The utility model discloses a logging gas chromatograph total hydrocarbon detects quantitative sampling device, including six -way valve system, dosing pipe, the six -way valve system includes that the six -way valve drives actuating cylinder, six -way valve, and wherein the six -way valve drives actuating cylinder and is used for driving the six -way valve and rotates and change the air flue, six holes are seted up to the six -way valve, and six -way valve and hydrogen FID, dosing pipe, hydrogen pipe, total hydrocarbon sample gas union coupling, six -way valve drive actuating cylinder and connect the air hose, hydrogen pipe and air hose are still equallyd divide and are do not communicate to hydrogen FID. The utility model relates to a simply, not only can make the total hydrocarbon detect the quantification, can also improve the precision that the total hydrocarbon detected, enlarge chromatographic linear range, reduce logging gas chromatograph manufacturing cost simultaneously.