Bacterial cellulose is a common research additive in the paper industry because it has unique and favorable characteristics. In this study, the effect of adding bacterial cellulose to an alkyl ketene dimer (AKD) sizing agent was investigated to optimize the dosage of bacterial cellulose, the retention system (cationic starch (CS), cationic polyacrylamide (CPAM)), and the sizing enhancement agents (polyamideamine-epichlorohydrin (PAE) and chitosan). The results showed that the addition of bacterial cellulose had a negative effect on AKD sizing. Meanwhile, the addition of 5% bacterial fiber had a slight but negligible effect on paper sizing. The retention system improved AKD sizing and the dual retention system with CS, and CPAM improved sizing up to 60%. When 0.2% PAE and chitosan were added simultaneously, the sizing degree increased by 42.8% and 47.6%, respectively.