With fresh lemon as raw materials,the influence of drying temperature,hot air volume,lemon piece thickness and hot air direction on lemon slices dried by tunnel hot air was investigated. Dehydration and drying rate curves were obtained by digital tunnel drying experimental device. Further,the experimental data were fitted by SAS8. 0 software and the lemon tunnel drying model was established. The result showed : the drying temperature( T),hot air volume( V),lemon slice thickness( P) and wind direction( X) all have a certain influence on the characteristics of dried lemon slices. Thin layer drying tunnel of lemon fits with Page model,the mathematical model is: ln(-lnMR) = ln(-0. 00054 + 1. 487E-6T +7. 771E-6V +0. 000062P-7. 29E-7X) +( 2. 4804-0. 0395 V +0. 00205T-0. 1869 P +0. 00129X) lnt.