A dissolving and mixing unit for automatically dissolving and mixing medicines includes: a support; a dissolving and mixing device mounted on the support and including two piercer bases and at least one dissolving and mixing channel, wherein each dissolving and mixing channel includes two piercers and an elastic infusion hose connecting the two piercers, and the two piercers of each dissolving and mixing channel are mounted on the two piercer bases respectively; a peristaltic pump mounted on the support and configured to squeeze the elastic infusion hose; first and second bottle-containing modules mounted on the support and configured to hold first and second medicine containers respectively; and a movement mechanism configured to drive at least one of the first bottle-containing module and one piercer base to move, and configured to drive at least one of the second bottle-containing module and the other piercer base to move.