Engine installation and removal trailers are important aircraft support equipments, which affect supportabilty and maintenability of jet fighters directly. US and European countries are world leaders in the field of engine I R trailer products and technologies, which are worth studying and used as a source of reference. There are different design features and specifications for engine I R trailers of different countries, different generations, different models. Therefore comparison is helpful to understand and digest engine I R trailer technologies. This article is based on large quantity of documents and reterences, and comparative studies are performed. By case analysis and vertical and horizontal comparative study,differences and sameness, advangtages and disadvantages of different trailer designs are distinguished. Features of development and evolution of trailers are recognized. Design technologies of trailers are mastered. The study work is expected to prvide important reference to design and development of advanced trailer product of China.