Shelf life simulation of fresh-cut lettuce was established when packed in two commercial packaging materials with four levels of O2 transmission rate (OTR) from 5 to 3875 cm3/m2/d/0.1 MPa. This study has established mathematic models coupling respiration of fresh-cut lettuce and Pseudomonas fluorescens, O2 and CO2 exchange, and microbial growth. The coupling models succeeded in predicting the dynamic change of O2 and CO2 in the headspace of biaxially oriented polyamide/low-density polyethylene (BOPA/LDPE) and polyethylene (PE) films. The coupling model contained Baranyi function showed the best fitting performance when predicting P. fluorescens growth. Quality attributes of lettuce showed that the BOPA/LDPE film with the lowest OTR significantly inhibited the P. fluorescens growth, extensively maintained color and texture, and extended the shelf life of fresh-cut lettuce. The established coupling models could be further utilized for evaluating the microbial safety and shelf life of other types of leaf vegetables where pseudomonads are dominant for spoilage.