In the process of tem sample preparation, ultra-thin slicing polluted problems are often occurred. This paper analyzes the causes of ultrathin section pollution and puts forward measures to improve section room environment, copper wire mesh support membrane and the rational use of slicing knife and knife trough to against the pollution in the process of ultrathin section production. Aimed at the pollution in section electronic dyeing process, it also puts forward some operational procedures which are to be strictly complied with in the process of dyeing liquid dispensing, correct methods and matters needing attention in the process of dyeing operations and clarified the necessary measures to effectively prevent electron microscope samples from pollution.