The invention provides an experimental device and method for gaseous product metering and drying sampling. The experimental device for gaseous product metering and drying sampling comprises a gas-liquid separating unit, a liquid level tracing balance metering unit, a drying unit and a sampling unit. By means of the experimental device, different quantities of experimental gaseous products, especially, gaseous products subjected to low-temperature gas-liquid separating can be automatically and accurately metered, and the influence of volatile light hydrocarbons with C4 or above on quantitation of the gaseous products can be eliminated; in combination with a dryer, the chromatographic analysis quality of obtained gas samples is improved; the requirement for collecting different gaseous products can be met through a sampler, the gaseous products can also be stored for a long term and conveniently transported, subsequent chromatograph sample introduction analysis can be conveniently carried out, and the metering precision can reach the level within 5 mL. Thus, a complete solution is provided for metering, drying and sampling of laboratory gaseous products.