The invention discloses a water and electricity consumption ratio clustering based abnormal water and electricity user detection method. The water and electricity consumption ratio clustering based abnormal water and electricity user detection method comprises the steps of firstly acquiring non-zero consumption data in water and electricity quantity data of users, calculating water to electricity ratio and electricity to water ratio of the non-zero consumption data, then conducting K-Means clustering calculation on the water to electricity ratio and electricity to water ratio to obtain abnormal individual data, and finally merging the abnormal individual data. The water and electricity consumption ratio clustering based abnormal water and electricity user detection method utilizes the water to electricity ratio and electricity to water ratio to integrate water consumption data and electricity consumption data of urban residents, utilizes a K-Means clustering algorithm to conduct abnormal detection on the integrated water to electricity ratio data and integrated electricity to water ratio data and then merges detection results to obtain final abnormal water and electricity users, the problem that water consumption data and electricity consumption data are separately detected and accordingly local convergence is caused is solved, and the purpose of efficiently detection the abnormal water and electricity users is achieved. Mistaken detection rate and missed detection rate of separated water consumption and electricity consumption detection are effectively reduced.