The well pattern adjustment is an effective method to further enhance recovery after the waterflooding reservoirs enter the ultra-high water cut stage. On the basis of the experimental device for three-dimensional（3D）physical simulation，waterflooding physical simulation experiments for positive-rhythm reservoirs were carried out under the basic well pattern，thinned well pattern，and infilled well pattern，and the development effects with and without adjustment of well patterns（well pattern thinning and well pattern infilling）were compared. It is found that compared with the basic well pattern，the thinned well pattern and the infilled well pattern can increase the final recoveries，and the increased recovery under thinned well pattern is greater than that under infilled well pattern. When the cumulative injected water volumes are the same，a higher injection rate leads to a higher waterflooding sweep coefficient and greater recovery. In addition，the final recovery with increased liquid production after well pattern adjustment is higher than that without increased liquid production. The waterflooding development effect under the thinned well pattern is superior to that under the basic well pattern and infilled well pattern，and increased liquid production after well pattern adjustment can give rise to enhanced oil recovery.