The invention relates to a method for sampling flammable and explosive high alkyne classes. The method includes the steps that a U-shaped pipe or a coil pipe into which flammable and explosive high alkyne class materials are fed is placed in a freezing medium for freezing and liquidation, wherein the freezing medium is liquid nitrogen or dry ice or frozen ethyl alcohol; the situation that liquid materials in a transparent rubber pipe connecting the U-shaped pipe or the coil pipe with a liquid hydrocarbon storage tank enter the liquid hydrocarbon storage tank is observed, according to the flow rate of the materials in the transparent rubber pipe, time during which the U-shaped pipe or the coil pipe is placed in the freezing medium and the contact area between the freezing medium and the U-shaped pipe or the coil pipe are controlled, and gaseous high alkyne pressure in the liquid hydrocarbon storage tank is adjusted, wherein the liquidation temperature of the flammable and explosive high alkyne classes is lower than or equal to -4 DEG C, and the pressure of the flammable and explosive high alkyne classes is smaller than or equal to 0.05 MPa; if the flow rate of the materials in the transparent rubber pipe is reduced or the materials stop flowing in the sampling process, sampling operation needs to be stopped, a heat source near a sampling point is used for unfreezing the frozen pipe, and the frozen pipe can be naturally unfrozen at environment temperature in summer. According to the method, the problems existing in flammable and explosive gas liquid collection and sampling are solved, and the sampling process is quick, effective and easy to operate.