ObjectiveTo investigate the status of microbial contamination in domestic washing machines, and provide basis for strengthening hygiene and health management. MethodsOnthespot sampling, laboratory microbial detection, and questionnaire survey were performed to investigate and analyze the hygiene treatment and microbial contamination of domestic washing machines of Beijing residents. ResultsSource water of 115 washing machines were collected, no bacteria were detected.The  total number of bacteria and fungi in washing water from 115 washing machines was 0-135 000 CFU/mL (13 206 CFU/mL on average)  and  0-690 CFU/mL (229 CFU/mL on average)  respectively. There was significant difference in  bacterial colony forming unit in washing water from washing machines of different length of service （P＜0.05）. 15 specimens of washing water from 15 washing machines were performed bacteriological detection, 17 kinds of bacteria were detected, most of which were opportunistic pathogenic bacteria. The major detected bacteria was  Pseudomonas aeruginosa (66.67%), followed by Staphylococcus aureus （60.00%） and Escherichia coli (53.33%). Survey showed that 32.17% of residents reflected the washing machines had peculiar smell and mildew spots, 48.69% of users chose to open the covers for ventilation,38.26% adopted local wiping and cleaning of filter bags, only 10.43% chose to soak with disinfectant, while 24.35% didn’t know how to deal with. ConclusionMicrobial contamination of domestic washing machines is serious, improper use and maintenance of washing machine is not conducive to health.