以乙二醛为底物、硝酸为氧化剂、亚硝酸钠为引发剂、盐酸为助催化剂，在具有特殊微结构的金属微通道反应器内连续生成乙醛酸。考察了物料摩尔比、硝酸质量分数、引发剂摩尔分数、助催化剂摩尔分数、温度和停留时间对反应的影响，结果表明，n（HNO₃）∶n（乙二醛）∶n（NaNO₂）∶n（HCl）=0.85∶1∶0.15∶0.2、硝酸质量分数为35%、温度为55℃、时间为2 min时，乙二醛转化率为80.3%，乙醛酸选择性达78.3%。与间歇反应相比，连续流微通道反应具有停留时间短、强传质传热的特点，大大缩短了反应时间，提高了反应效率，克服了硝化反应过程中出现的飞温现象，提升了本质安全等级，实现了乙二醛硝化的绿色安全高效合成。

Glyoxylic acid is synthesized by oxidation method in a continuous flow micro-channel reactor with special micro-structure,using glyoxal as substrate,nitric acid as oxidant,sodium nitrite as initiator,and hydrochloric acid as co-catalyst.The effects of several factors on oxidation are investigated,including feedstock molar ratio,mass concentration of nitric acid,molar concentrations of initiator and co-catalyst,temperature and residence time.Results show that the conversion of glyoxal reaches 80.3%,and the selectivity of glyoxylic acid reaches 78.3% when the concentration of nitric acid is 35%,n(HNO₃)∶n(glyoxal)∶n(NaNO₂)∶n(HCl)=0.85∶1∶0.15∶0.2,T=55℃,and t=2 min.Compared with batch reaction,the continuous flow micro-channel reaction has advantages of short residence time,strong mass transfer and heat transfer,which shorten greatly reaction time,improve reaction efficiency,and avoid the flying temperature phenomenon in the nitrification process.The intrinsic safety is improved,and green,safe and efficient synthesis of glyoxal nitration can be also realized.