Total least squares (TLS) is proposed to complete harmonic state estimation when parameter and measurement errors are both taken into consideration. The buses are partitioned into subsets of nonsource buses and suspicious buses, thereby reducing the number of unknown state variables. The validity and practicability of this approach is validated using the IEEE14bus harmonic testing system. The estimation precision is analyzed by random sampling 10 000 times in Matlab when measurement errors and parameter errors followed a Gaussian distribution. The results show that an accurate estimate can be obtained using TLS if parameter and measurement errors are considered.