The invention relates to a pretreatment method for measuring 14C abundance of an organic compound type sample. The method includes transferring carbon atoms in the organic compound into CO2 molecules through combustion, reacting CO2 with a NaOH solution to obtain a saturate NaHCO3 solution, heating the saturate NaHCO3 solution to obtain a saturate Na2CO3 solution, and adopting the saturate Na2CO3 solution for 14C abundance tests. The invention also provides a device used for the method. The device mainly comprises an oxygen cylinder, a nitrogen cylinder, a cold trap A, a three-way stopcock A, a combustion chamber, a cold trap B, a stone, a cold trap C, a three-way stopcock B, a conical flask, a cold trap D, a three-way stopcock C, a U-shaped gas sample collector, a three-way stopcock D, a vacuum gauge, a vacuometer, a piston D and a vacuum pump. On the basis of guaranteeing the measuring accuracy, the method largely simplifies the chemical treatment process, increases the time efficiency and reduced the cost.