To solve the temperature monitoring problem of syngas pipeline in the existing coal gasification process,a distributed optical fiber temperature measuring system based on Raman scattering is studied. A high temperature resistant sensing fiber with stainless steel coating is developed to simulate the temperature distribution around syngas pipeline. The high temperature resistant optical fiber with 434.6 m length is laid on the site of the syngas pipeline for experimental research. The experimental results show that the distributed optical fiber temperature measurement system based on Raman scattering has a temperature measurement range of 0～350℃,the temperature measurement error is ±2℃,and the spatial resolution is 0.5 m. The system can complete the online temperature monitoring of coal gasification syngas pipeline,and at the same time it can spatially locate the temperature anomalies.