Slug flow trap is a key equipment in condensate oil and gas field development, it has large size, complex loading conditions, high operating pressure and large investment cost. Reasonable and reliable design is very important to its safe operation and investment­saving. In order to assure its proper operation, it is necessary to study on its operating characteristics, loading, strength calculation method and inspection and test regulations and to form a complete set of mature and reliable slug flow trap design methods. Summarized are successful experiences in slug flow traps designed by China Petroleum Engineering Co., Ltd. Southwest Company, conducted is analysis on working principle and loads of slug flow traps, described are their structure features and multi-saddle equipment strength, material selection and manufacturing requirements and formed are a complete set of design, manufacture and inspection technologies of volumetric slug flow traps, which can provide valuable reference for design standard supplement.