The medium- and long-chain triacylglycerols (MLCTs) rich in α-linolenic acid could be used as an anti-obesity, functional material in food industry. MLCTs could overcome the shortcomings of the LCTs and MCTs, and provide the human body with essential fatty acids and faster energy supply. Enzymatic interesterification of perilla oil and MCTs was performed to prepare the MLCTs rich in α-linolenic acid, the reaction were catalysed by Lipozyme RM IM. The effects of enzyme loading, ratio of MCTs to perilla oil, reaction time and reaction temperature on the yield of MLCT were studied. The results showed that the reaction achieved more than 70% yield of MLCTs in triacylglycerols under the conditions of 6% Lipozyme RM IM, 40% MCT and 60% perilla oil at 60℃ for 4h. Deodorization was a traditional deacidification method, in consideration of processing costs and equipment reconstruction costs, the two-stages deodorization was used to update into a two-stages deodorization to better remove the undesired by-products after interesterification reaction, providing a method for the physical deacidification of polyunsaturated oils in practice. The free fatty acids of the interesterified products were removed significantly, the triacylglycerols were more than 97% in the refined products, and the trans fatty acids could be limited within 1%. In the purified products, more than 85% of the long-chain fatty acids were occupying the sn-2 position in triacylglycerols, and the total α-linolenic were more than 40%.