采用 PY-GC-MS(快速热裂解 － 色质联用)对 5-羟甲基糠醛(5-HMF)进行热裂解实验，发现裂解产物中将近 86%为呋喃环类物质，同时存在小分子物质，表明其热解主要为侧链降解，但也存在呋喃环的开环断裂． 结合原位红外光谱分析，实时监测 5-HMF 热裂解产物随反应过程的转化规律，发现在130 ～230℃之间主要生成糠醛、5-甲基糠醛，250℃后主要生成2-糠醇及5-乙酰甲氧基-2-糠醛，这两者的生成持续至反应中后期;作为 5-HMF热解最主要产物的 2，5-呋喃二甲醛的生成则在整个反应过程持续进行． 结合快速热解及原位红外实验结果，推测 5-HMF 的热解机理如下:侧链羟甲基处连续两次脱氢生成 2，5-呋喃二甲醛是最主要的反应，羟甲基去羟基后加氢生成 5-甲基糠醛，羟甲基侧链及醛基侧链的整体断裂分别生成糠醛及糠醇，在此基础上还会发生二次裂解反应生成 2-甲基呋喃．

Pyrolysis experiments of 5-hydroxymethyl furfural (5-HMF) were conducted and the product composi-tion was detected by using a PY-GC-MS analyzer． The results show that nearly 86% of the pyrolysis product is fu-ran ring-contained substance，and that a certain amount of small molecules exist in the product，which means that the pyrolysis process of 5-HMF is mainly a side-chain degradation process concomitantly with the fracture of furan rings． Moreover，the converting law of the product in the pyrolysis process was supervised in real time via in-situ FT-IR． The results show that furfural and 5-methyl furfural mainly form when the temperature ranges from 130 to 230℃，furfuryl alcohol and 5-formyl-2-furfurylacetate mainly form after 250 ℃ and the formation continues to the middle and later periods of the whole process，while the dominant pyrolysis product of 5-HMF，namely furan-2，5-dicarbaldehyde，forms throughout the whole pyrolysis process． According to the results obtained from fast pyrolysis experiment and in-situ FT-IR，the pyrolysis mechanism is speculated as follows: as the most primary reaction，fu-ran-2，5-dicarbaldehyde forms from two consecutive dehydrogenations and then converts into 5-methyl furfural after the dehydroxylation and hydrogenation of hydroxymethyl; the whole fracture of hydroxymethyl side chain and alde-hyde group side chain leads to the formation of furfural and furfuryl alcohol; and 2-methylfuran may be produced via the secondary pyrolysis of furfural and furfuryl alcohol．