NOVELTY - A natural gas high calorific value detecting method involves utilizing agilent GC7890 chromatograph-hydrogen flame ionization detector, alumina/sulfur capillary column, carrier gas comprising helium, hydrogen and nitrogen, needle-shaped adjusting valve, and sampling, followed by maintaining furnace temperature, controlling flow velocity and sampling volume, setting integration with area normalization through chromatographic working station, and calculating volume of natural gas and natural gas high calorific value by using equations given in the specification.    USE - Method for detecting natural gas high calorific value.    ADVANTAGE - The method enables detecting natural gas high calorific value with high precision and low detection limit in a simple, inexpensive and rapid manner.    DETAILED DESCRIPTION - A natural gas high calorific value detecting method involves utilizing agilent GC7890 chromatograph-hydrogen flame ionization detector, alumina/sulfur capillary column with length of 50 m, an inner diameter of 0.88 mm and thickness of 15.0 mu m, carrier gas comprising helium , hydrogen and nitrogen with purity of 99.99%, needle-shaped adjusting valve, sampling, utilizing stainless steel sampling cylinders, pressure of more than 10 MPa, and temperature of 60-50 degrees C, gas sample loop of 0.5 ml, automatic gas sampling valve to 0.01 MPa, transferring initial temperature of 50 degrees C and detector temperature of 250 degrees C. The furnace temperature is maintained at 40 degrees C for 2 minutes. The temperature is raised to 150 degrees C at a speed of 5 degrees C/minute and raised to 190 degrees C at a speed of 18 degrees C/minute for 5 minutes, followed by controlling flow velocity of 0.2 ml/minute and sampling volume of 0.5 ml, utilizing helium gas as carrier with flow rate of 30 ml/minute in chromatography, controlling temperature of 120 degrees C, opening air valve and hydrogen pipeline valve, flow rate of air to be 400 ml/minute, flow rate of hydrogen to be 35 ml/minute, and sampling steel cylinder air inlet valve with air inlet flow rate of 300-350 ml/minute. The air inlet valve is closed, followed by opening cylinder valve to release gas inside cylinder to maintain cylinder gas pressure at 0.1 MPa by avoiding nitrogen, oxygen, air reverse osmosis and other impurities into the cylinder, setting integration with area normalization through chromatographic working station, and calculating volume of natural gas and natural gas high calorific value by using equations given in the specification.