The aim of the study was to explore the effect of distilled water on killing tumour cells attached to the surgery instruments during operation. Tumour cells were collected from the suspected tumour cell-contaminated surgery instruments and then cultured. Then the tumour cells were treated by distilled water at different gradient temperature for different time periods. The morphology of the tumour cells was observed by inverted microscope after hematoxylin-eosin staining. The results showed that positive tumour cell culture rate was 34.3%. After soaked in distilled water for 60 s at 55°C, the tumour cells were inactive, and the death rate was 100%. We also found that no active cells were seen to grow adherently after recultured. In conclusion, tumour cells can be killed by distilled water for 60 s at 55°C, which provides a new fast and low-cost tumour-free technique to inactivate tumour cells attached to surgery instruments.