An intra-band combiner-divider, comprising: a first-level duplexer, comprising a downlink signal output end and an uplink signal input end, wherein the first-level duplexer is configured to perform separate signal receiving and sending in a downlink direction and perform combined signal receiving and sending in an uplink direction; an intra-band combination unit, wherein an input end of the intra-band combination unit is connected to the downlink signal output end, and the intra-band combination unit is configured to combine downlink signals in a same band; an intra-band division unit, wherein an output end of the intra-band division unit is connected to the uplink signal input end, and the intra-band division unit is configured to divide uplink signals in a same band; and a second-level duplexer, comprising a downlink signal input end and an uplink signal output end, wherein the downlink signal input end is connected to an output end of the intra-band combination unit, the uplink signal output end is connected to an input end of the intra-band division unit, and the second-level duplexer is configured to perform combined signal receiving and sending in the downlink direction and perform separate signal receiving and sending in the uplink direction; wherein the intra-band combination unit is further configured to isolate the downlink signals in the same band according to different carrier signals; wherein the intra-band combination unit comprises: a first isolation module that is configured to isolate the downlink signals in the same band, and a first combination module and a second combination module that are configured to combine the downlink signals in the same band, wherein:one end of the first combination module is connected to the downlink signal output end, the other end of the first combination module is connected to one end of the first isolation module, the other end of the first isolation module is connected to one end of the second combination module, and the other end of the second combination module is connected to the downlink signal input end; wherein the first-level duplexer comprises at least one narrowband duplexer. a first-level duplexer, comprising a downlink signal output end and an uplink signal input end, wherein the first-level duplexer is configured to perform separate signal receiving and sending in a downlink direction and perform combined signal receiving and sending in an uplink direction; an intra-band combination unit, wherein an input end of the intra-band combination unit is connected to the downlink signal output end, and the intra-band combination unit is configured to combine downlink signals in a same band; an intra-band division unit, wherein an output end of the intra-band division unit is connected to the uplink signal input end, and the intra-band division unit is configured to divide uplink signals in a same band; and a second-level duplexer, comprising a downlink signal input end and an uplink signal output end, wherein the downlink signal input end is connected to an output end of the intra-band combination unit, the uplink signal output end is connected to an input end of the intra-band division unit, and the second-level duplexer is configured to perform combined signal receiving and sending in the downlink direction and perform separate signal receiving and sending in the uplink direction; wherein the intra-band combination unit is further configured to isolate the downlink signals in the same band according to different carrier signals; wherein the intra-band combination unit comprises: a first isolation module that is configured to isolate the downlink signals in the same band, and a first combination module and a second combination module that are configured to combine the downlink signals in the same band, wherein:one end of the first combination module is connected to the downlink signal output end, the other end of the first combination module is connected to one end of the first isolation module, the other end of the first isolation module is connected to one end of the second combination module, and the other end of the second combination module is connected to the downlink signal input end; wherein the first-level duplexer comprises at least one narrowband duplexer. a first isolation module that is configured to isolate the downlink signals in the same band, and a first combination module and a second combination module that are configured to combine the downlink signals in the same band, wherein:one end of the first combination module is connected to the downlink signal output end, the other end of the first combination module is connected to one end of the first isolation module, the other end of the first isolation module is connected to one end of the second combination module, and the other end of the second combination module is connected to the downlink signal input end; wherein the first-level duplexer comprises at least one narrowband duplexer.