Changes in microorganisms during fruit preservation and the effect of different preservative treatments (0.05% sodium benzoate; 0.03% sodium dehydroacetate; 0.05, 0.10, 0.15, and 0.20% chitosan; ultraviolet light; ultraviolet light + 0.025% sodium benzoate; ultraviolet light + 0.038% sodium benzoate) on microbial control of preserved fruit (Taiwan Wumei) were examined. The results indicated that the microbial counts (bacteria, mold, and yeast) increased over time during the storage period (five months); however, the growth rate was relatively slow. Sodium dehydroacetate and chitosan could obviously inhibit microbial growth in preserved fruit (Taiwan Wumei), and the antibacterial effect of sodium dehydroacetate was even better than that of sodium benzoate. Therefore, the use of sodium dehydroacetate in preserving fruits will be beneficial. Additionally, ultraviolet treatment inhibited microbial growth in preserved fruit (Taiwan Wumei). Hence, it is recommended to introduce ultraviolet irradiation treatment into commercial production processes, to achieve the dual effects of microbial control and a reduction in sodium benzoate requirement for preserving fruit.