A post-harvest preservation technology suitable for litchi was investigated and the effects on the low temperature storage quality of ‘Guiwei’ litchi were determined using individual pre-cooling methods and in combination with nano-cinnamaldehyde. The results indicated that litchi treated with iced water pre-cooling is prone to browning and rotting during cold storage, with a significantly higher susceptibility index and browning index than other treatments. The total soluble solids, titratable acid, and vitamin C contents of litchi treated with iced water pre-cooling decreased at a more rapid rate, and the activities of polyphenol oxidase and peroxidase peaked at 5.98 and 91.33 U/g, respectively, on the 8th day. Chilled air pre-cooling was more effective than other cooling methods in delaying pericarp browning and maintaining the nutritional value of litchi. The shelf life of litchi pre-cooled with cold air was extended by more than 6 days compared with iced water pre-cooled litchi. In addition, nano-cinnamaldehyde treatment significantly reduced the presence of diseased litchi pre-cooled with iced water and cold air, by 62.29% and 44.49%, respectively, on the 21st day, compared with iced-water precooling and chilled air pre-cooling, individually. This results indicates that nano-cinnamaldehyde is effective in inhibiting the presence of post-harvest diseases in litchi. Moreover, the browning of iced water pre-cooled litchi was reduced by nano-cinnamaldehyde treatment, resulting in a remarkably lower browning index (2.76 vs. 3.51) on the 15th day. In conclusion, chilled air pre-cooling is more suitable than other cooling methods for ‘Guiwei’ litchi and nano-cinnamaldehyde treatment is effective in inhibiting the presence of post-harvest diseases and improving the post-harvest quality of litchi.