The invention discloses an intermediate frequency signal processing device and method based on the LTE230. The method relates to a downlink signal processing unit, and the downlink signal processing unit comprises a downlink primary signal processing unit and a downlink secondary signal processing unit. The downlink primary signal processing unit comprises M downlink primary frequency mixers and a downlink half-band filter, wherein M is a positive integer which is larger than or equal to one. The downlink secondary signal processing unit comprises a downlink secondary frequency mixer, a downlink CIC filter and a downlink low pass filter. The M downlink primary frequency mixers sequentially pass through the downlink half-band filter, the downlink secondary frequency mixer and the downlink CIC filter to be connected with the downlink low pass filter. According to the intermediate frequency signal processing device and method based on the LTE230, the number of sub bands which can be processed simultaneously is far larger than the number of sub bands in public network application, and excellent adjacent channel inhibiting ability at the narrowest 25 KHz sub band width can be provided.