Abstract: According to one embodiment, the gas analyzer system comprises a gas adaptor, a light guide tube and a measure case. The gas adaptor is used for guiding a gas to be detected, wherein the gas is flowed in the gas adaptor along a flow direction. The light guide tube embedded in the gas adaptor, wherein the light guide tube has a light source end and a sensor end, the light guide tube has at least one aperture for the gas entering the light guide tube, and a normal vector of a cross surface defined by the aperture has an angle with respect to the gas inhale direction, wherein the angle is not 180 degrees. The measuring case for accommodating the gas adaptor comprises a light source corresponding to the light source end and a sensor corresponding to the sensor end of the light guide tube.