The invention relates to the field of tower design and discloses a 1,100kV extra-high voltage direct-current power transmission line tower series planning method. The method comprises the following steps of dividing weather combinations of multiple sections according to weather condition survey value combinations; setting a merging process according to required conditions such as weather, a topographic condition, a conductor and ground wire type, a polar spacing, altitude, an overvoltage multiple, a gap and the like, and obtaining multiple tower series; performing tower optimization ranking under a non-constraint condition, and obtaining a horizontal span, a vertical span and a tower height of each tower series; selecting multiple linear tower series with different horizontal spans to perform comparison of comprehensive cost, horizontal span utilization rate and the like, and determining horizontal span parameters of an optimal linear tower series (such as 4, 5, 6, 7 set and the like); and according to an optimal ranking scheme, performing statistics on the usage rates of the vertical span, the tower height and the Kv value of the determined optimal linear tower series by utilizing a distribution probability and a cumulative probability, obtaining a value range with a relatively high usage rate, and determining usage condition parameters of the linear tower series.