The%20portable%20electricity%20meter%20devices%20can%20measure%20and%20monitor%20the%20electricity%20actually%20used%20by%20the%20user%20during%20the%20process%20of%20electricity%20meter%20replacement%20and%20ensure%20the%20normal%20power%20consumption%20of%20the%20user.%20A%20comprehensive%20evaluation%20method%20of%20portable%20electricity%20meter%20devices%20based%20on%20the%20improved%20optimization%20of%20membership%20functions%20is%20proposed%20in%20this%20paper.%20Firstly,%20a%20comprehensive%20evaluation%20index%20system%20of%20portable%20electricity%20meter%20devices%20is%20established from both%20the%20commercial%20and%20technical%20aspects.%20Secondly,%20in%20order to avoid%20the%20problems%20of%20singleness%20and%20subjectivity%20in%20the%20existing%20methods%20of%20membership%20function%20selection%20and%20index%20weight%20determination,%20an%20improved%20optimization%20construction%20method%20of%20membership%20functions%20is%20proposed to improve%20the%20reliability%20of%20the%20evaluation%20results.%20Then%20the%20weight%20vector%20of%20each%20index%20is%20determined%20by%20the%20method%20of%20order%20relation%20and%20mean%20square%20error,%20and%20the%20steps%20of%20the%20comprehensive%20evaluation%20algorithm%20of%20the%20portable%20electricity%20meter%20devices%20are%20given.%20The%20case%20example%20shows%20that%20the%20comprehensive%20evaluation%20method%20proposed%20in%20this%20paper%20can%20effectively%20evaluate%20the%20portable%20electricity%20meter%20devices%20with%20higher%20reliability.