The present invention relates to a coal gasification device online analyzing sample pretreatment system, which comprises a four stage filter device and a cyclone refrigerator controlled by intelligent temperature. A first stage filter comprises a self-cooling tube, a cooling tank and a self-cleaning condensation liquid removing filter tank in order. A back-flushing valve and a temperature sensor which are connected with a steam tube are arranged on the top of the self-cleaning condensation liquid removing filter tank. A second stage filter is a paper filter. A third stage filter is a self-cleaning tee filter. A fourth filter is a molecular sieve filter. The second stage filter and the fourth stage filter adopt redundant structures. A temperature controller which is connected with the temperature sensor controls the interruption of an electromagnetic valve which is connected with the cyclone refrigerator. So the adjustable temperature control and the intelligent control of the refrigerator cold blast rate are realized. The coal gasification sample is treated by multi stage cooling, removing water and dust removal filtration. So the temperature, the water content and the dust content of the sample are ensured to meet the requirement before entering an analytical instrument.