Cassava (Manihot esculenta Crantz) is an important food crop in tropical and subtropical areas. SWEETs participate in a variety of plant activities, including sugar transport, reproduction and development, plant stress, and interaction with pathogens, which play an important role in plant development. In order to clarify the function of SWEET in the growth and development of cassava, sugar transporter MeSWEET18 was cloned from Cassava South China 9 (SC9) for bioinformatics analysis and verified sugar transport capacity by yeast experiment in this study. The expression trend of MeSWEET18 in cassava in different organ, different developmental stages and under abiotic stress were determined via qRT-PCR method. MeSWEET18 contained a 714 bp open reading frame (ORF) encoding a protein of 237 amino acids residues with predicted molecular mass of 25.94 kDa and theoretical isoelectric point of 6.57. Through instability index (II) analysis by ProtParam, the instability index (II) of the protein encoded by MeSWEET18 was 37.50, indicating the protein of MeSWEET18 as stable. MeSWEET18 was a typical membrane protein with a conserved domain MtN3_slv at the N-terminal and a PQ-Loop Super family conserved domain at the C-terminal and seven transmembrane domains. ProtScale predicted that MeSWEET18 was a hydrophilic protein. Phylogenetic tree analysis revealed that MeSWEET18 belonged to Clade IV. MeSWEET18 was in the same evolutionary tree as AtSWEET16 and AtSWEET17. Alignment of amino acid sequences revealed 53.23% homology between MeSWEET18 and AtSWEET16, and 56.05%homology between MeSWEET18 and AtSWEET17. Yeast functional complementarity tests showed that MeSWEET18 primarily transported fructose. qRT-PCR analysis showed that MeSWEET18 was highly expressed in tuberous roots during the expansion and decreased sharply at maturity of cassava tuberous roots, while the expression levels in leaf, petiole and stem increased with the development of cassava, and reached the maximum at the maturity stage of cassava. qRT-PCR analysis showed that MeSWEET18 was significantly affected by fructose when the hydroponic seedlings of SC9 were treated with sucrose, glucose and fructose solutions under dark conditions. The hydroponic seedlings of SC9 were subjected to abiotic stress including high salt (8 g/L NaCl) stress, drought (100 mmol/L mannitol) stress, oxidation (10% H₂O₂) stress and low temperature (15 ℃ for 24 h, then reduced to 4 ℃ for 24 h) stress. The results show that MeSWEET18 is expressed differently in leaf, petiole, stem and root under abiotic stress. It can be speculated that MeSWEET18 play an important role under abiotic stress in cassava.