A sampling device for an ion migration spectrometer, which is used to introduce a sample to be detected into an inlet of a migration pipe of the ion migration spectrometer, wherein the sampling device comprises: an inner sleeve part, inside of which an inner cavity is defined, one end of the inner sleeve part is capable of connecting with the inlet of the migration pipe via an inner channel, and the other end of the inner sleeve part is equipped with an inner end cap having an inner opening, the inner channel comprises a branch channel which is connected with the inner cavity; and an outer sleeve part, which is configured as an eccentric sleeve that is coaxial with the inner sleeve part and able to rotate with respect to the inner sleeve part, so as to form a sleeve cavity between the inner sleeve part and the outer sleeve part, one end of the outer sleeve part is configured with at least one connecting opening that is connectable with the inner channel, and the other end of the outer sleeve part is equipped with an outer end cap, on which a first outer opening connectable with the inner opening and a second outer opening connectable with the sleeve cavity are configured, wherein, the outer end cap can rotate as the outer sleeve part rotates, wherein, the inner channel further comprises a branch channel which is connected with the sleeve cavity via the connecting opening; the outer end cap is configured to be able to rotate between a first location and a second location with respect to the inner end cap, so as to selectively introduce a sample to be detected into the inner channel via one of the inner cavity and the sleeve cavity; a heating part is configured outside the inner sleeve part, for heating the inner cavity to form a thermal resolving cavity, in which a solid sample to be detected is heated to form a gaseous sample to be detected. an inner sleeve part, inside of which an inner cavity is defined, one end of the inner sleeve part is capable of connecting with the inlet of the migration pipe via an inner channel, and the other end of the inner sleeve part is equipped with an inner end cap having an inner opening, the inner channel comprises a branch channel which is connected with the inner cavity; and an outer sleeve part, which is configured as an eccentric sleeve that is coaxial with the inner sleeve part and able to rotate with respect to the inner sleeve part, so as to form a sleeve cavity between the inner sleeve part and the outer sleeve part, one end of the outer sleeve part is configured with at least one connecting opening that is connectable with the inner channel, and the other end of the outer sleeve part is equipped with an outer end cap, on which a first outer opening connectable with the inner opening and a second outer opening connectable with the sleeve cavity are configured, wherein, the outer end cap can rotate as the outer sleeve part rotates, wherein, the inner channel further comprises a branch channel which is connected with the sleeve cavity via the connecting opening; the outer end cap is configured to be able to rotate between a first location and a second location with respect to the inner end cap, so as to selectively introduce a sample to be detected into the inner channel via one of the inner cavity and the sleeve cavity; a heating part is configured outside the inner sleeve part, for heating the inner cavity to form a thermal resolving cavity, in which a solid sample to be detected is heated to form a gaseous sample to be detected.