The invention relates to a least squares improved location method of anchor node optimal selection, in particular, a minimum error propagation-based least squares location method of anchor node optimal selection. According to the minimum error propagation-based least squares location method of anchor node optimal selection of the invention, a bilateral equivalence distance estimation method is adopted to obtain a plurality of sample values of distance estimations from an unknown node to each anchor node; statistic analysis is performed on the plurality of sample values, so that the statistic mean and statistical standard deviation of each distance estimation value are obtained; and a dynamic sliding window method and a single-round scanning method are used to obtain a plurality of distance estimation results, the product value of the distance statistical mean and statistical standard deviation of the distance estimation of the distance estimation results being minimum, and corresponding anchor nodes are selected to construct a least squares location equation set; and the least squares criterion is used to obtain a high-precision positioning result.