In order to reduce loss of alkaloids to improve chewing quality during the heat treatment process of areca, the dried areca were used as test materials to investigate the effect of factors about boiling wash and drying after wash as well as drying after flavoring on mass transfer of alkaloids in the shell of betel nut. Based on the mass transfer characteristics of alkaloids, the optimum parameters of heat treatment process were designed. The results showed that alkaloids from nuclear of areca will be dissolved out and transfer in the shell, then diffusing from the shell to the surface, the transfer and diffusion rate of alkaloids was closely related to the washing temperature and time, drying temperature and time as well as drying process. At the same time, the optimal process parameters for washing was that the areca were washed two times with 75 ℃ drinking water, each time for 50 min, the optimal drying process parameters after washing was drying temperature 50 ℃ for 80 min, and the optimal drying process after flavoring was that the first drying phase was 70 ℃ for 30 min the second drying phase was 80 ℃for 20 min, and the loss of alkaloids was 8.86%. The characteristics of mass transfer and the optimal processing parameters in the process of heat treatment can provide a useful reference for the processing of chewing areca.