Herein, we present a novel electrochemical sensor for the determination of chloramphenicol (CAP), which is based on multiwalled carbon nanotubes@molecularly imprinted polymer (MWCNTs@MIP), mesoporous carbon (CKM-3) and three-dimensional porous graphene (P-r-GO). Firstly, 3-hexadecyl-1-vinylimidazolium chloride (C16VimCl) was synthetized by using 1-vinylimidazole and 1-chlorohexadecane as precursors. Then, C16VImCl was used to improve the dispersion of MWCNT and as monomer to prepare MIP on MWCNT surface to obtain MWCNTs@MIP. After that, the obtained MWCNTs@MIP was coated on the CKM-3 and P-r-GO modified glassy carbon electrode to construct an electrochemical sensor for the determination of CAP. The parameters concerning this assay strategy were carefully considered. Under the optimal conditions, the electrochemical sensor offered an excellent response for CAP. The linear response ranges were 5.0×10−9–5×10−7molL−1 and 5.0×10−7–4.0×10−6, respectively, and the detection limit was 1.0×10−10molL−1. The electrochemical sensor was applied to determine CAP in real samples with satisfactory results. •A novel MWCNTs@molecularly imprinted polymer (MWCNTs@MIP) was designed.•A new functional monomer was adopted for the preparation of MWCNTs@MIP.•Mesoporous carbon and three-dimensional graphene enhanced the response signal.•The sensor offered a response for chloramphenicol from 0.005 to 4.0μmolL−1.