The invention discloses a multimode antenna and a base station, wherein the multimode antenna comprises a CDMA (code division multiple access) dual-polar antenna, consisting of a plurality of linearly arranged elements and used for transmitting and receiving radio-frequency signals in a CDMA system, two MIMO (multiple input multiple output) dual-polar antennae, both consisting of a plurality of linearly arranged elements and used for transmitting and receiving radio-frequency signals in an LTE (long term evolution) system, and two MIMO dual-polar antennae which are arranged over and under a central element of the CDMA dual-polar antenna in a vertical direction respectively and are used for nesting elements in the two MIMO dual-polar antennae into the elements of the CDMA dual-polar antenna or inserting the elements into the two MIMO dual-polar antennae between the elements of the CDMA dual-polar antenna according to the element interval of the CDMA dual-polar antenna and the element interval of each MIMO dual-polar antenna. In combination with an antenna element nesting technology and a vertical MIMO antenna isolating technology, the CDMA dual-polar antenna and the two MIMO dual-polar antennae can be integrated into a physical antenna.