The mass transfer process in the reciprocating sieve plate extraction column(RPEC)was studied.Based on the single droplet mass transfer model，the scale-up model of RPEC was established with mathematical statistics.In this model，flux，tray spacing，amplitude and frequency should be kept invariable when HOXP（apparent height of a transfer unit）was calculated.In a RPEC of diameter 100 mm，the experiment was carried out with lincomycin-n-butanol-acid water.The experiment results showed that：HOX（true height of a transfer unit）was related to system physical properties，apparent velocity，input energy（amplitude A×frequency f），but had nothing to do with the column diameter and axial mixing.The model caculation showed that HOX decreased with the increase of input energy but was little affected by the change in flux.HOXD（dispersion height of a transfer unit）is a function of column diameter D，input energy，flux Us and system physical properties.The mass transfer in RPEC could be divided into two stages.The model could describe the first stage better，in which the increase of input energy and flux intensifies the mass transfer and reduces HOXD effectively.But it could not describe the second stage，in which the influence of axial mixing on mass transfer dominates.The scale-up model was used to design a RPEC of diameter 325 mm

and the results showed that the prediction error of this model was less than 20%.